Search results for " isolation"

Vibrational spectroscopy of trans and cis deuterated formic acid (HCOOD): Anharmonic calculations and experiments in argon and neon matrices

2010

The absorption spectra of trans and cis conformers of deuterated formic acid (HCOOD) isolated in argon and neon matrices are analyzed in the mid-infrared and near-infrared spectral regions (7900–450 cm � 1 ). Vibrational excitation by narrow-band IR radiation is used to convert the lower-energy trans conformer to the higher-energy cis form. A large number of overtone and combination bands are identified. The results of anharmonic vibrational calculations (CC-VSCF) for both conformers are reported and compared to the experimental spectra.

Theoretical characterization of the photochemical reaction CO2 + O(3P) → CO + O2 related to experiments in solid krypton

2020

Abstract Formation and decomposition of the complex of carbon dioxide and atomic oxygen are characterized by quantum chemistry methods aiming to rationalize experimental studies in solid krypton. The observed FTIR spectra reflected the temporal evolution of the system after irradiation showing the bands of reactants, intermediates and products. Advanced quantum chemistry calculations show that the T-shape complex CO2…O(3P) can be formed in the matrix. Its excitation by the 193 nm light results in the charge-transfer state CO2+…O−, which evolves to the reaction intermediate CO3. The latter species decomposes to CO + O2 following pathways on the excited state energy surfaces.

Unstable behaviour of normally-off GaN E-HEMT under short-circuit

2018

The short-circuit capability of power switching devices plays an important role in fault detection and the protection of power circuits. In this work, an experimental study on the short-circuit (SC) capability of commercial 600 V Gallium Nitride enhancement-mode high-electron-mobility transistors (E-HEMT) is presented. A different failure mechanism has been identified for commercial p-doped GaN gate (p-GaN) HEMT and metal-insulator-semiconductor (MIS) HEMT. In addition to the well known thermal breakdown, a premature breakdown is shown on both GaN HEMTs, triggered by hot electron trapping at the surface, which demonstrates that current commercial GaN HEMTs has requirements for improving the…

Laser irradiation of ZnO:Al/Ag/ZnO:Al multilayers for electrical isolation in thin film photovoltaics

2013

Laser irradiation of ZnO:Al/Ag/ZnO:Al transparent contacts is investigated for segmentation purposes. The quality of the irradiated areas has been experimentally evaluated by separation resistance measurements, and the results are complemented with a thermal model used for numerical simulations of the laser process. The presence of the Ag interlayer plays two key effects on the laser scribing process by increasing the maximum temperature reached in the structure and accelerating the cool down process. These evidences can promote the use of ultra-thin ZnO:Al/ Ag/ZnO:Al electrode in large-area products, such as for solar modules. © 2013 Crupi et al.; licensee Springer.

Low Cost Electrical Current Sensors with Extremely Wide Measurement Range

2015

A new electrical current measurement system is presented. It features the ability to dynamically and automatically change its measurement range to the sensed current amplitude without user action. It also exhibits galvanic isolation and near zero insertion loss characteristics.

High vibrational overtone excitation‐induced conformational isomerization of glycolic acid in solid argon matrix

2018

University experience of a tutorial action programme during the COVID-19 lockdown in teacher training at a Valencian University (Spain)

2021

Coronavirus disease 2019 (COVID-19) is perceived as the worst modern-times pandemic. This entirely new health situation entailed a new challenge to the education system. To our knowledge, the impact of alternative teaching methods derived from the social distancing imposed by COVID-19 on university student perception in teacher education has not been investigated. The aim of this study was to analyse an educative experience developed in a Faculty of Teaching from March 2020 to July 2020 in order to overcome the challenge imposed by COVID-19. A qualitative approach was used for data collection and analysis using four information sources: (a) The final written documents developed by the worki…

Hell on earth: Textual reflections on the experience of mental illness

2012

Background: Some people who by themselves or by others are understood as having mental health problems have written autobiographies about their experiences. Aims: The aim of this study is to explore how people write about their experiences of being mentally ill. Method: Twelve Scandinavian autobiographies were studied using content analysis based on phenomenology and hermeneutics. Results: Three themes were identified: feeling like a stranger in life and places, the transformation of life experiences into questions of disease and feeling ashamed. Conclusions: People’s experiences of being mentally ill might be understood as the result of medical constructions unsuitable for the persons them…

Minimum displacement design of base isolation devices

2014

Correlation-Based Cell Degradation Detection for Operational Fault Detection in Cellular Wireless Base-Stations

2013

The management and troubleshooting of faults in mobile radio networks are challenging as the complexity of radio networks is increasing. A proactive approach to system failures is needed to reduce the number of outages and to reduce the duration of outages in the operational network in order to meet operator’s requirements on network availability, robustness, coverage, capacity and service quality. Automation is needed to protect the operational expenses of t he network. Through a good performance of the network element and a low failure probability the network can operate more efficiently reducing the necessity for equipment investments. We present a new method that utilizes the correlatio…