Characterization of ultrathin gate dielectrics formed by in-situ steam generation with nitrogen postprocessing

We examined ultrathin films produced by in-situ steam generation (ISSG), ISSG with NO anneal, ISSG with remote plasma nitridation (RPN), and rapid thermal oxidation (RTO). Capacitance-voltage measurements performed on these films indicated an equivalent oxide thickness (EOT) in the range of 1.6–2.5 nm. The nitrogen postprocessing made it possible to achieve thinner EOTs while keeping theleakage current density below 10⁻² A/cm² at V_g=−1.5 V. Total x-ray fluorescence (TXRF) analysis on the films yielded a transition metal concentration less than 5×10¹⁰ atoms/cm². Atomic force microscopy (AFM) measurements yielded microroughness values of 0.18–0.2 nm, which were conformal to the starting material surface microroughness. High-resolution transmission electron microscopy (HRTEM) images showed physical thicknesses ranging from 2.0–3.0 nm, which were used, in conjunction with the EOTs, to calculate effective dielectric constants for the films. Low energy (500 eV) secondary ion mass spectrometry (SIMS) measurements performed on the ISSG + NO and ISSG + RPN films showed sharply different [N] profiles.     

Fifteen-month follow-up of social skills and cognitive-relaxation approaches to general anger reduction.

This article presents a 15-mo follow-up of a study by J. L. Deffenbacher, G. A. Thwaites, T. L. Wallace, and E. R. Oetting (see record 1994-38333-001) that compared inductive social skills training (ISST) with skill assembly social skills training and cognitive-relaxation coping skills (CRCS) interventions for general anger reduction in college students. Compared with the control group at 15-mo follow-up, counseled groups reported lower trait anger, general anger, anger across many situations, and anger-related physiological arousal; less anger suppression and outward negative expression; and greater calm, controlled expression. ISST and CRCS participants also reported less anger in their worst ongoing, angering situation. More counseled participants showed clinically significant improvement on trait anger as well. In none of these comparisons did counseled groups differ among themselves. No treatment effects were found on nontargeted assertiveness and trait anxiety. Results are discussed in terms of long-term efficacy of treatments and of the importance of long-term follow-up. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hydrogen permeation in optical fibres with hermetic carbon coatings

Hydrogen permeation has been measured for optical fibres with hermetic carbon coatings. Data obtained at elevated temperatures and high hydrogen pressures lead to predictions of extremely low permeation rates at typical operating conditions. In situ loss measurements have shown the existence of a lag time, during which no hydrogen reaches a fibre's interior     

Coordination in co-located agile software development projects

Agile software development provides a way to organise the complex task of multi-participant software development while accommodating constant project change. Agile software development is well accepted in the practitioner community but there is little understanding of how such projects achieve effective coordination, which is known to be critical in successful software projects. A theoretical model of coordination in the agile software development context is presented based on empirical data from three cases of co-located agile software development. Many practices in these projects act as coordination mechanisms, which together form a coordination strategy. Coordination strategy in this context has three components: synchronisation, structure, and boundary spanning. Coordination effectiveness has two components: implicit and explicit. The theoretical model of coordination in agile software development projects proposes that an agile coordination strategy increases coordination effectiveness. This model has application for practitioners who want to select appropriate practices from agile methods to ensure they achieve coordination coverage in their project. For the field of information systems development, this theory contributes to knowledge of coordination and coordination effectiveness in the context of agile software development.     

Der werkstoffmechanische Hintergrund für Qualitätsforderungen an hochbeanspruchte Scheiben für Luftfahrttriebwereke

Quality Requirements for High Stressed Engine Disks in View of Fracture Mechanics With respect to recent experience the useful application of high strength materials for engine disks implies some consequences, which take into account the influence of defects on the LCF live and the accelerated growth of short cracks. Crack initiation life in the conventional sense is no more an economical and reliable measure for life cycle limitation. Instead of this, the number of cycles to fracture should be used as a basis, taking into account that there is an upper limit in the diameter of primary defects. Increasing the strength of (and consequently the stress in) a material, there also must be improved its “quality” (in terms of maximum diameter of defects). Up to now the mutual interrelations are quantitatively not wellknown. So this is an important field for further evaluations.     

Identity management based on adaptive puzzles to protect P2P systems from Sybil attacks

The Sybil attack consists on the indiscriminate creation of counterfeit identities, by a malicious user (attacker), in large-scale, dynamic distributed systems (for example, Peer-to-Peer). An effective approach to tackle this attack consists in establishing computational puzzles to be solved prior to granting new identities. Solutions based on this approach have the potential to slow down the assignment of identities to malicious users, but unfortunately may affect normal users as well. To address this problem, we propose the use of adaptive computational puzzles as an approach to limit the spread of Sybils. The key idea is to estimate a trust score of the source from which identity requests depart, calculated as a proportion of the number of identities already granted to (the) user(s) associated to that source, in regard to the average of identities granted to users associated to other sources. The higher the frequency (the) user(s) associated to a source obtain(s) identities, the lower the trust score of that source and, consequently, the higher the complexity of the puzzle to be solved. An in-depth analysis of both (i) the performance of our mechanism under various parameter and environment settings, and (ii) the results achieved with an experimental evaluation, considering real-life traces from a Peer-to-Peer file sharing community, has shown the effectiveness of the proposed mechanism in limiting the spread of Sybil identities. While comparatively more complex puzzles were assigned to potential attackers, legitimate users were minimally penalized with easier-to-solve puzzles.     

A novel bulk micromachined electrostatic microvalve with acurved-compliant structure applicable for a pneumatic tactile display

Recent success of microelectromechanical systems (MEMS) in projection displays have raised similar expectation for an efficient, low power, affordable, full-page and pneumatic tactile display. Such design has not been achieved by the conventional technology but could bring significant improvement to current refreshable Braille displays. This paper demonstrates a novel bulk-micromachined electrostatic microvalve suitable for a pneumatic tactile display. The microvalve, a silicon perforated diaphragm juxtaposed to a silicon inlet orifice, requires relatively low closing voltage against a large supply differential pressure and flow rate, i.e., 72.9 V-rms for 19.3 kPa and 85 mi/min. Such an attractive characteristic is due to its unique curved-compliant structure that has, unlike other electrostatic microvalves, no tolerance for any initial air gap between its electrodes. As a design tool, a mechanical model of the microvalve is introduced based on the lubrication theory and large plate deflection theory. The model is established on a steady-state coupled field problem of fluid-solid mechanics. Reynolds and von-Karman equations were simultaneously solved for the microvalve geometry by finite difference approximation and double Fourier series expansion. The results of the model and experiments are compared and found to be in good agreement with a relative error less than 10%