Two Words, One Meaning: Evidence of Automatic Co-Activation of Translation Equivalents

Research on the processing of translations offers important insights on how bilinguals negotiate the representation of words from two languages in one mind and one brain. Evidence so far has shown that translation equivalents effectively activate each other as well as their shared concept even when translations lack of any formal overlap (i.e., non-cognates) and even when one of them is presented subliminally, namely under masked priming conditions. In the lexical decision studies testing masked translation priming effects with unbalanced bilinguals a remarkably stable pattern emerges: larger effects in the dominant (L1) to the non-dominant (L2) translation direction, than vice versa. Interestingly, this asymmetry vanishes when simultaneous and balanced bilinguals are tested, suggesting that the linguistic profile of the bilinguals could be determining the pattern of cross-language lexico-semantic activation across the L2 learning trajectory. The present study aims to detect whether L2 proficiency is the critical variable rendering the otherwise asymmetric cross-language activation of translations obtained in the lexical decision task into symmetric. Non-cognate masked translation priming effects were examined with three groups of Greek (L1)–English (L2) unbalanced bilinguals, differing exclusively at their level of L2 proficiency. Although increased L2 proficiency led to improved overall L2 performance, masked translation priming effects were virtually identical across the three groups, yielding in all cases significant but asymmetric effects (i.e., larger effects in the L1 → L2 than in the L2 → L1 translation direction). These findings show that proficiency does not modulate masked translation priming effects at intermediate levels, and that a native-like level of L2 proficiency is needed for symmetric effects to emerge. They furthermore, pose important constraints on the operation of the mechanisms underlying the development of cross-language lexico-semantic links

Space charge accumulation in polymeric high voltage DC cable systems

One of the intrinsic properties of the polymeric high voltage (HV) direct current (DC) cable insulation is the accumulation of electrostatic charges. Accumulated charges distort the initial Laplacian distribution of the electric field, leading to a local field enhancement that may cause insulation degradation and premature breakdown of the system. The general objective of the present study is to obtain a better understanding of the major factors that control the space charge processes in polymeric HVDC cable systems. In order to achieve this goal, two main factors of influence have been investigated. 1) Cable accessories, i.e. cable joints and cable terminations, are considered to be the weakest part of a cable system, because of the presence of a dielectric interface between the cable insulation and that of the accessory. This thesis aims at a better knowledge of the polarization phenomena occurring at dielectric interfaces. To that purpose, an accurate methodology has been developed for the experimental study of the space charge behavior at the dielectric interface. The pulsed electro-acoustic (PEA) method for the measurement of space charge has been reviewed in case of dielectric interfaces. Secondly, space charge accumulation has been experimentally observed at the dielectric interfaces of different test specimens. 2) Across the insulation of HVDC cable systems a temperature drop is present when the cable carries a current. This thesis aims to provide a better understanding about the mechanisms responsible for space charge accumulation when a temperature drop is present across the insulation of the cable system. To that purpose, a physical model has been developed for the prediction of space charge dynamics and electric field in loaded HVDC cable systems. The physical model has been validated by means of laboratory investigation.Electrical Engineering, Mathematics and Computer Scienc

Space charge measurements on multi-dielectrics by means of the pulsed electroacoustic method

Electrical Engineering, Mathematics and Computer Scienc

Codesign of an impulse generator and miniaturized antennas for IR-UWB

Electrical Engineering, Mathematics and Computer Scienc

PD recurrence in cavities at different energizing methods

Electrical Engineering, Mathematics and Computer Scienc

Calculation and measurement of space charge in MV-size xxtruded cables systems under load conditions

A load current in dc high voltage cables results in a temperature drop across the insulation and hence a radial distribution of the insulation conductivity is found. Direct consequence is an accumulation of space charge in the bulk of the nsulation, that may significantly affect its reliability. This phenomenon was modeled in terms of the macroscopic properties of the cable insulation and a numerical procedure was developed for the calculation of the time-dependent space charge and electric field in extruded-type cables. Results of calculations were compared to those of space charge measurements performed on MV-size XLPE cables at different values for the temperature drop. The analysis of the results indicates that the space charge induced by the temperature drop is measurable and that its magnitude and location can be reasonably well estimated by means of the proposed numerical procedure. Moreover, different space charge accumulation mechanisms could be distinguished taking into account the knowledge obtained of the space charge distribution induced by the temperature drop.Electrical Engineering, Mathematics and Computer Scienc

On-site Testing and PD Diagnosis of High Voltage Power Cables

In addition to after-laying of new-installed high voltage (HV) power cables the use of on-site non-destructive on-site testing and diagnosis of service aged power cables is becoming an important issue to determine the actual condition of the cable systems and to determine the future performances. In this paper based on field experience an overview is presented on on-site testing and partial discharge diagnosis of HV power cables with regard to on-site testing methods: energizing, diagnostic aspects, possibilities and implications for new and service aged power cables.Electrical Sustainable EnergyElectrical Engineering, Mathematics and Computer Scienc