Comparación socioeconómica de las empresas agrarias de producción ecológica y convencional en Aragón, España : Problemas y oportunidades

El trabajo presenta los problemas y oportunidades de la agricultura ecológica en Aragón, España. Con esta finalidad, se compara la agricultura ecológica con la convencional tanto en los aspectos socioeconómicos como medioambientales. Como base de esta comparativa, se presentan algunos de los principios básicos de la agricultura ecológica y su estructura contable de costes, obtenida a través de un trabajo de campo en Aragón y bases de datos oficiales, así como datos sobre su consumo y distribución; finalmente se sugieren algunas vías de actuación pública que pueden apoyar las oportunidades de la agricultura ecológica.

Comparación socioeconómica de las empresas agrarias de producción ecológica y convencional en Aragón, España : Problemas y oportunidades

El trabajo presenta los problemas y oportunidades de la agricultura ecológica en Aragón, España. Con esta finalidad, se compara la agricultura ecológica con la convencional tanto en los aspectos socioeconómicos como medioambientales. Como base de esta comparativa, se presentan algunos de los principios básicos de la agricultura ecológica y su estructura contable de costes, obtenida a través de un trabajo de campo en Aragón y bases de datos oficiales, así como datos sobre su consumo y distribución; finalmente se sugieren algunas vías de actuación pública que pueden apoyar las oportunidades de la agricultura ecológica.

Comparación socioeconómica de las empresas agrarias de producción ecológica y convencional en Aragón, España : Problemas y oportunidades

El trabajo presenta los problemas y oportunidades de la agricultura ecológica en Aragón, España. Con esta finalidad, se compara la agricultura ecológica con la convencional tanto en los aspectos socioeconómicos como medioambientales. Como base de esta comparativa, se presentan algunos de los principios básicos de la agricultura ecológica y su estructura contable de costes, obtenida a través de un trabajo de campo en Aragón y bases de datos oficiales, así como datos sobre su consumo y distribución; finalmente se sugieren algunas vías de actuación pública que pueden apoyar las oportunidades de la agricultura ecológica.

A comparison between conceptual clustering and conventional clustering

Clustering is a process of partitioning a given set of patterns into meaningful groups. The clustering process can be viewed as consisting of the following three phases: (i) feature selection phase, (ii) classification phase, and (iii) description generation phase. Conventional clustering algorithms implicitly use knowledge about the clustering environment to a large extent in the feature selection phase. This reduces the need for the environmental knowledge in the remaining two phases, permitting the usage of simple numerical measure of similarity in the classification phase. Conceptual clustering algorithms proposed by Michalski and Stepp [IEEE Trans. PAMI, PAMI-5, 396–410 (1983)] and Stepp and Michalski [Artif. Intell., pp. 43–69 (1986)] make use of the knowledge about the clustering environment in the form of a set of predefined concepts to compute the conceptual cohesiveness during the classification phase. Michalski and Stepp [IEEE Trans. PAMI, PAMI-5, 396–410 (1983)] have argued that the results obtained with the conceptual clustering algorithms are superior to conventional methods of numerical classification. However, this claim was not supported by the experimental results obtained by Dale [IEEE Trans. PAMI, PAMI-7, 241–244 (1985)]. In this paper a theoretical framework, based on an intuitively appealing set of axioms, is developed to characterize the equivalence between the conceptual clustering and conventional clustering. In other words, it is shown that any classification obtained using conceptual clustering can also be obtained using conventional clustering and vice versa.

A Comparison of mechanical and tribological behavior of nanostructured and conventional WC-12Co detonation-sprayed coatings

In the present study, WC-12Co coatings were deposited by detonation-spraying technique using conventional and nanostructured WC-12Co feedstock at four different oxy/fuel ratios (OF ratio). The coatings exhibited the presence of phases like W2C and W due to the decarburization of the WC phase, and the proportions of these phases were higher in the nano WC-12Co coatings compared with conventional WC-12Co coatings. Coating hardness and fracture toughness were measured. The tribological performance of coatings was examined under dry sand rubber wheel abrasion wear, and solid particle erosion wear conditions. The mechanical and wear properties of coatings were influenced by degree of decarburization and more so in the case of nanostructured WC-Co coatings. The results indicate that the extent of decarburization has a substantial influence on the elastic modulus of the coating which in turn is related to the extent of intersplat cracking of the coating.

Performance comparison for 12 V lead-carbon hybrid ultracapacitors with substrate-integrated and conventional pasted positive plates

Lead-carbon hybrid ultracapacitors comprise positive lead dioxide plates of the lead-acid battery and negative plates of carbon-based electrical double-layer capacitors (EDLCs). Accordingly, a lead-carbon hybrid ultracapacitor has the features of both the battery and that of an EDLC. In this study, the development and performance comparison between the two types of lead-carbon hybrid ultracapacitors, namely those with substrate-integrated and conventional pasted positive plates, is presented as such a study is lacking in the literature. The study suggests that the faradaic efficiencies for both types of lead-carbon hybrid ultracapacitors are comparable. However, their capacitance values as well as energy and power densities differ significantly. For substrate-integrated positive plate hybrid ultracapacitor, capacitance and energy density values are lower, but power density values are higher than pasted positive plate lead-carbon hybrid ultracapacitors due to their shorter response time. Accordingly, internal resistance values are also lower for substrate-integrated lead-carbon hybrid ultracapacitors. Both types of lead-carbon hybrid ultracapacitors exhibit good cycle life of 100,000 pulse charge-discharge cycles with only a nominal loss in their capacitance values.

A comparison between maximum length sequence and conventional auditory brainstem responses as a screening tool for auditory sensitivity

This paper compares conventional auditory brainstem response tests (ABRs) and Maximum Length Sequence auditory brainstem response tests (MLS ABRs). The results found that the faster MLS ABRs could prove an accurate screening tool for auditory sensitivity.

Comparison of the strain distribution obtained from multi scale and conventional approaches to modelling extrusion

An investigation of the application of a multi scale CAFE model to prediction of the strain localization phenomena in industrial processes, such as extrusion, is presented in this work. Extrusion involves the formation of a strong strain localization zone, which influences the final product microstructure and may lead to a coarse grain layer close to the surface. Modelling of the shape of this zone and prediction of the strain magnitude will allow computer aided design of the extrusion process and optimisation of the technological parameters with respect to the microstructure and properties of the products. Thus, the particular objective of this work is comparison of the FE and CAFE predictions of strain localization in the shear zone area in extrusion. Advantages and disadvantages of the developed CAFE model are also discussed on the basis of the simulation results.

Lifecycle cost and CO2 emission comparison of conventional and rationalized bridges

The construction industry consumes a great deal of natural resources and energy in constructing, maintaining and demolishing their products such as buildings and bridges. These activities lead significant impacts on global and regional environments in addition to their economic expenses. In this research, the lifecycle cost (LCC) and lifecycle CO₂ (LCCO₂) emission of newly developed bridges, including the minimized girder, rationalized box-girder and rationalized truss bridges, are quantified and compared with those of the conventional I-girder, box-girder and truss bridges. It was found that the newly developed types of bridges have lower values in both LCC and LCCO₂ than the corresponding conventional bridges do. The effects of span lengths on LCC and LCCO₂ are studied for both conventional and rationalized bridges. The characteristics of LCC and LCCO₂ are investigated over the lifecycle of a bridge including its construction, maintenance and replacement stages.