Energy Comparison between a Load Sensing System and Electro-Hydraulic Solutions Applied to a 9-Ton Excavator

With the increasingly stringent regulations on air quality and the consequent emission limits for internal combustion engines, researchers are concentrating on studying new solutions for improving efficiency and energy saving even in off-road mobile machines. To achieve this task, pump-controlled or displacement-controlled systems have inspired interest for applications in offroad working machines. Generally, these systems are derived from the union of a hydraulic machine coupled to an electric one to create compact components that could be installed near the actuator. The object of study of this work is a 9-ton excavator, whose hydraulic circuit is grounded on load sensing logic. The validated mathematical model, created previously in the Simcenter Amesim© environment, represents the starting point for developing electro-hydraulic solutions. Electric components have been inserted to create different architectures, both with open-and closed-circuit layouts, in order to compare the energy efficiency of the different configurations with respect to the traditional load sensing system. The simulations of a typical working cycle show the energy benefits of electrohydraulic solutions that allow for drastically reducing the mechanical energy required by the diesel engine and, consequently, the fuel consumption. This is mainly possible because of the elimination of directional valves and pressure compensators, which are necessary in a load sensing circuit, but are also a source of great energy dissipations. The results show that closed-circuit solutions produce the greatest benefits, with higher energy efficiencies than the open-circuit solution. Furthermore, closed-circuit configurations require fewer components, allowing for more compact and lighter solutions, as well as being cheaper

Extraction and Partial Characterization of Proteolytic Activities from the Cell Surface of Lactobacillus helveticus Zuc2

Abstract Proteolytic activities were extracted from a dairy Lactobacillus helveticus strain and partially characterized. A first cell envelope proteinase (CEP) was extracted using a high ionic strength buffer, both in the presence and in the absence of Ca 2+ . Moreover, cell treatment by 5 M LiCl allowed for the selective removal of the S-layer protein and CEP, suggesting an enzyme ionic linkage to the cell envelope similar to that observed for the Slayer structure. The enzyme specificity against α s1 -CN (f1–23) showed unusual activity on the Lys 3 -His 4 bond compared with other proteinases of the same species. A second proteinase appeared to be linked to the cell membrane because it was extractable only after membrane disgregation by detergents. Its specificity against CN fractions and α s1 -CN (f1–23) was different from that of the first CEP; moreover, the measured activity was lower than that of CEP

Narrativas transmediáticas en España: cuatro ficciones en busca de un destino cross-media

Durante casi una década las narrativas transmediáticas han formado parte de la agenda de los estudios de medios, con frecuencia desde perspectivas económicas y sociológicas, alejadas de cualquier análisis textual de la materia. Este artículo, basado en la tradición semiótica y narratológica, analiza cuatro producciones transmediáticas de ficción producidas en España: Las tres mellizas, Infidels, Serrallonga y Águila Roja. Tras una primera parte dedicada al corpus teórico del trabajo, las tres secciones siguientes están centradas ofrecen una primera exploración de un panorama desigual, necesitado de nuevos conceptos y taxonomías que ayuden a una mayor comprensión del fenómeno transmediático

Beyond the TV borders: Second screen as a tool for audience engagement

The growing popularity of mobile connected devices has transformed the way TV content is conceived and consumed. Interacting with these devices while watching TV is a trending behaviour that represents a challenge for the TV industry as this interaction often distracts viewers from the TV content. Consumers use the second screen to retrieve further information about narratives, characters, purchasing goods and researching on products and services advertised. In a scenario of systematic live and linear TV audience erosion and ad-skipping broadcasters, marketers and producers are continuously looking for new ways to leverage different media strategies to keep TV viewers engaged with the primary content, promoting consumers’ loyalty and generating more revenue flows. In this paper, a set of second screen cases was selected to ground a reflection on how second screen solutions may be applied to foster the viewer and consumer engagement

The Spermatophore in Glossina morsitans morsitans: Insights into Male Contributions to Reproduction.

Male Seminal Fluid Proteins (SFPs) transferred during copulation modulate female reproductive physiology and behavior, impacting sperm storage/use, ovulation, oviposition, and remating receptivity. These capabilities make them ideal targets for developing novel methods of insect disease vector control. Little is known about the nature of SFPs in the viviparous tsetse flies (Diptera: Glossinidae), vectors of Human and Animal African trypanosomiasis. In tsetse, male ejaculate is assembled into a capsule-like spermatophore structure visible post-copulation in the female uterus. We applied high-throughput approaches to uncover the composition of the spermatophore in Glossina morsitans morsitans. We found that both male accessory glands and testes contribute to its formation. The male accessory glands produce a small number of abundant novel proteins with yet unknown functions, in addition to enzyme inhibitors and peptidase regulators. The testes contribute sperm in addition to a diverse array of less abundant proteins associated with binding, oxidoreductase/transferase activities, cytoskeletal and lipid/carbohydrate transporter functions. Proteins encoded by female-biased genes are also found in the spermatophore. About half of the proteins display sequence conservation relative to other Diptera, and low similarity to SFPs from other studied species, possibly reflecting both their fast evolutionary pace and the divergent nature of tsetse's viviparous biology

Coletânea de artigos do ano 2004 da Embrapa Suínos e Aves.

bitstream/item/58190/1/doc96.pd