Cross‐correlation‐based trans‐impedance amplifier for current noise measurements

This work proposes a cross‐correlation‐based trans‐impedance amplifier for current noise measurements in the low‐frequency range. The proposed solution is compared with the classical cross‐correlation trans‐impedance amplifier showing a lower background noise. Furthermore, a three‐step measurement method, based on the new trans‐impedance amplifier, is proposed to cancel the residual background noise. SPICE simulations and noise measurements performed on prototype circuits demonstrate the validity of the proposed approach. Copyright © 2008 John Wiley & Sons, Ltd.     

Pressure stability field of Mg-perovskite under deep mantle conditions: A topological approach based on Bader's analysis coupled with catastrophe theory

The pressure stability field of the Mg-perovskite phase was investigated by characterizing the evolution of the electron arrangement in the crystal. Ab initio calculations of the perovskite structures in the range 0–185?GPa were performed at the HF/DFT (Hartree-Fock/Density Functional Theory) exchange–correlation terms level. The electron densities, calculated throughout the ab-initio wave functions, were analysed by means of the Bader's theory, coupled with Thom's catastrophe theory. To the best of our knowledge the approach is used for the first time. The topological results show the occurrence of two topological anomalies at P~20?GPa and P~110?GPa which delineate the pressure range where Mg-perovskite is stable.The paper accomplishes the twofold objectives of providing a contribution in shading light into the behaviour of the dominant component of the Earth's lower mantle across the D’’ layer and of proposing a novel approach in predicting the stability of a compound at extreme conditions.     

Analysis of environmental benefits resulting from use of hydrogen technology in handling operations at airports

Airports and nearby areas are currently facing an increasing pollution due to the growth of air transport traffic. Airport air pollution is produced not only by aircraft during landing and take-off cycles but also by the ground support equipment (GSE) during the airport handling activities. This paper investigates the potential of hydrogen as an alternative fuel for GSE vehicles to mitigate the airport air pollution. For this purpose, a methodology is developed to assess the environmental benefits attainable with the introduction of hydrogen technology for GSE vehicles powered by proton exchange membrane (PEM) fuel cells. This methodology compares, for a given scenario, the direct emissions produced by fuel combustion and the indirect emissions related to fuel production for both diesel and hydrogen technologies. Steam methane reforming and electrolysis technologies are investigated for the production of gaseous hydrogen at the airport. The pollutants investigated comprise carbon monoxide, total hydrocarbons, nitrogen oxides, sulphur oxides, particulate matter and volatile organic compounds. The main inputs for the methodology are the number of air transport movements, the aircraft fleet mix, the turnaround times for handling operations, the type of GSEs used, and the ratio of GSE vehicles converted to hydrogen (type, power installed, etc.). A preliminary cost analysis of a ground power unit powered by PEM fuel cells is also presented. The airport planners and policy makers can use this study to define a feasible environmental policy based on the use of new technologies such as hydrogen.     

Pleural drainage vs video-assisted minimally invasive surgery in the treatment of spontaneous pneumothorax. A retrospective study

The most frequent cause of spontaneous pneumothorax is bleb's disease of the lung. Considering that, pnx s. has a remarkable bent for relapsing, we think that it's necessary an aggressive treatment to resolve it. That's because pleural drainage is useful for a symptomatic resolution, VATS for an etiologycal one. To value the real efficacy of the treatment of VATS, we have effected a retrospective research between two classes of patients suffering from pnx s. admitted in our Institute from 1987 until 1991, one treated with pleural drainage (class A, 11 patients) and the other with VATS (class B, 13 patients). 1) Patients treated with pleural drainage were nearly double compared to class B. 2) In class A, the mean value of drainages were nearly double compared to class B. 3) Class A had a number of relapses 10 times more compared to B. 4) Considering the period of hospitalization, class A had a value nearly triple compared to B. 5) We've noticed that the mean value of the cost for episode of pnx s. in class A was more than 15% compared to class B and the cost for patient in class A was nearly double than in class B. We can affirm that, for the treatment of pnx s., the method of VATS rappresents a real success. We're passed from the "symptomatological treatment" of it to an aetiological one, joined to the prophylaxis of the relapse.     

A new archival approach to the study of values and value--Behavior relations: Validation of the value lexicon.

The present effort employs a new archival approach to study values and value- behavior relations, which is likely to be particularly useful in applied settings. A value lexicon was developed on the basis of the Schwartz (1992) value theory to extract lexical indicators of values from texts. The convergent, discriminant, and predictive validity of this measure was established using American newspaper content from 1900 to 2000 vis-à-vis existing self-report measures of values and objective indicators of value-expressive behaviors. Results provide empirical support for the use of the value lexicon to study values and value- behavior relations. First, the value lexicon demonstrated convergence with self-report responses of values. Second, values in American newspapers were associated with objective indicators of their corresponding value-expressive behaviors compared with noncorresponding value- expressive behaviors. Third, patterns of values over this 101-year period exhibited meaningful fluctuations with major historical and political events. The discussion describes new possibilities for future research on values in many applied settings with the value lexicon. The discussion also suggests that the principles of the value lexicon could be adopted to measure other psychological constructs of interest to applied psychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Finite-Dynamic Model for Infinite Media: Corrected Solution of Viscous Boundary Efficiency

This paper presents the corrected development of viscous boundary efficiency initially proposed by Lysmer and Kuhlemeyer. The expressions of the energy ratio are given, in accordance with the original numerical results, and confirm the authors’ recommendations to minimize the reflected energy of body waves that impinge on the artificial boundary.     

Self-subjugation among women: Exposure to sexist ideology, self-objectification, and the protective function of the need to avoid closure.

Despite extensive evidence confirming the negative consequences of self-objectification, direct experimental evidence concerning its environmental antecedents is scarce. Incidental exposure to sexist cues was employed in 3 experiments to investigate its effect on self-objectification variables. Consistent with system justification theory, exposure to benevolent and complementary forms of sexism, but not hostile or no sexism, increased state self-objectification, self-surveillance, and body shame among women but not men in Experiment 1. In Experiment 2, we replicated these effects and demonstrated that they are specific to self-objectification and not due to a more general self-focus. In addition, following exposure to benevolent sexism only, women planned more future behaviors pertaining to appearance management than did men; this effect was mediated by self-surveillance and body shame. Experiment 3 revealed that the need to avoid closure might afford women some protection against self-objectification in the context of sexist ideology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electric field and charge distribution imaging with sub-micron resolution in an organic Thin-Film Transistor

Here we show how Stark spectroscopy, coupled with confocal microscopy, is able to directly map the electric field in an n-type Copper-Fluorinated Phthalocyanine Thin-Film Transistor (TFT) under different operating conditions. To this extent, we locally probe Electro-Reflectance, with a nominal spatial resolution better than 500 nm, exploiting the fact that the detected signal is directly proportional to the square of the local field on the probe volume. This electric field imaging technique has unique advantages because it is non-invasive, since it exploits low incident power and because it probes the existing field in the bulk rather than the surface. Combining the experimental data with numerical modeling, it is possible not only to reconstruct the space charge profile in the few-nanometer thick accumulation layer, but also to extract the AC electron mobility.