Design and implementation of an automatic measurement system for the characterization of power MOSFETs

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Torsion pendulum facility for direct force measurements of LISA GRS related disturbances

A four mass torsion pendulum facility for testing of the LISA GRS is under development in Trento. With a LISA-like test mass suspended off-axis with respect to the pendulum fiber, the facility allows for a direct measurement of surface force disturbances arising in the GRS. We present here results with a prototype pendulum integrated with very large-gap sensors, which allows an estimate of the intrinsic pendulum noise floor in the absence of sensor related force noise. The apparatus has shown a torque noise near to its mechanical thermal noise limit, and would allow to place upper limits on GRS related disturbances with a best sensitivity of 300 fN/Hz^(1/2) at 1mHz, a factor 50 from the LISA goal. Also, we discuss the characterization of the gravity gradient noise, one environmental noise source that could limit the apparatus performances, and report on the status of development of the facility.Comment: Submitted to Proceedings of the 6th International LISA Symposium, AIP Conference Proceedings 200

Improving Human Reliability Analysis for Railway Systems Using Fuzzy Logic

The International Union of Railway provides an annually safety report highlighting that human factor is one of the main causes of railway accidents every year. Consequently, the study of human reliability is fundamental, and it must be included within a complete reliability assessment for every railway-related system. However, currently RARA (Railway Action Reliability Assessment) is the only approach available in literature that considers human task specifically customized for railway applications. The main disadvantages of RARA are the impact of expert’s subjectivity and the difficulty of a numerical assessment for the model parameters in absence of an exhaustive error and accident database. This manuscript introduces an innovative fuzzy method for the assessment of human factor in safety-critical systems for railway applications to address the problems highlighted above. Fuzzy logic allows to simplify the assessment of the model parameters by means of linguistic variables more resemblant to human cognitive process. Moreover, it deals with uncertain and incomplete data much better than classical deterministic approach and it minimizes the subjectivity of the analyst evaluation. The output of the proposed algorithm is the result of a fuzzy interval arithmetic, $\alpha$ -cut theory and centroid defuzzification procedure. The proposed method has been applied to the human operations carried out on a railway signaling system. Four human tasks and two scenarios have been simulated to analyze the performance of the proposed algorithm. Finally, the results of the method are compared with the classical RARA procedure underline compliant results obtain with a simpler, less complex and more intuitive approach

Supervivencia de una pequeña población trasladada de Procolobus kirkii en la isla de Pemba

A survey to evaluate the distribution of Procolobus kirkii on Pemba island (Tanzania) was conducted, 20 years after they had been translocated from Zanzibar in the Ngezi forest park. A team of both expert and trained observers, guided by the authors, censused 68.3 linear km of forest, corresponding to an estimated area of 3.5 km2 (63.6%) of the protected Ngezi forested area of 5.5 km2. Nineteen groups of Cercopithecus aethiops were observed, with a total of 166 animals and an estimated density of 47.43 individuals per km2, and only one troop of Procolobus kirkii. Supplemented by interviewing the local people we obtained an estimate of 15–30 P. kirkii, including a small troop outside the protected area. This small population survived but did not increase, possibly due to adverse relations with humans.Se realizó un estudio para evaluar la distribución de Procolobus kirkii en la isla de Pemba (Tanzania), veinte años después de que fuera trasladada desde Zanzíbar al Parque Ngezi. Un equipo de observadores expertos y entrenados, guiados por los autores, efectuó un censo a lo largo de 68,3 km lineales de bosque, correspondiente a un área estimada de 3,5 km2 (63,6%) del área protegida del bosque de Ngezi de 5,5 km2. Se observaron 19 grupos de Cercopithecus aethiops, con un total de 166 animales y una densidad estimada de 47,43 individuos/km2, y sólo un grupo de Procolobus kirkii. Complementando los datos con entrevistas a la población local se obtuvo una estimación de 15–30 ejemplares de P. kirkii, incluyendo un pequeño grupo localizado fuera del área protegida. Este pequeño grupo sobrevivía pero no se incrementaba en número, posiblemente debido a las relaciones adversas con los humanos

Ecological Distribution and Oenological Characterization of Native Saccharomyces cerevisiae in an Organic Winery

The relation between regional yeast biota and the organoleptic characteristics of wines has attracted growing attention among winemakers. In this work, the dynamics of a native Saccharomyces cerevisiae population was investigated in an organic winery. In this regard, the occurrence and the persistence of native S. cerevisiae were evaluated in the vineyard and winery and during spontaneous fermentation of two nonconsecutive vintages. From a total of 98 strains, nine different S. cerevisiae biotypes were identified that were distributed through the whole winemaking process, and five of them persisted in both vintages. The results of the oenological characterization of the dominant biotypes (I and II) show a fermentation behavior comparable to that exhibited by three common commercial starter strains, exhibiting specific aromatic profiles. Biotype I was characterized by some fruity aroma compounds, such as isoamyl acetate and ethyl octanoate, while biotype II was differentiated by ethyl hexanoate, nerol, and β-damascenone production also in relation to the fermentation temperature. These results indicate that the specificity of these resident strains should be used as starter cultures to obtain wines with distinctive aromatic profiles

Entangled Two-Dimensional Coordination Networks: A General Survey

Many of the reported species exhibit the intriguing feature of interpenetration or other types of entanglements. The properties of these materials are related not only to their molecular structures but also to the topology of the individual networks as well as to the way in which the individual nets are entangled. Different synthetic procedures have been developed to attain a certain control of entanglement in coordination networks, and recently some reviews have appeared that are focused on factors governing the entanglements, having in mind their potential applications. However, these analyses are mostly devoted to 3D networks thanks to the great wealth of data on interpenetration. Simplification of a network that contains 2-loops can lead to complete disappearance of the entanglement, and therefore such networks were picked out into a separate group