Gallium nitride (GaN) is the main component of modern-day high electron mobility transistor electronic devices due to its favorable electronic properties. As electronic devices become smaller with more complex architecture, the ability to deposit high-quality GaN films at low temperature is required. Herein, we report a new highly volatile Ga(III) triazenide precursor and demonstrate its ability to deposit high-quality epitaxial GaN by atomic layer deposition (ALD). This new Ga(III) triazenide precursor, the first hexacoordinated M–N bonded Ga(III) precursor used in a vapor deposition process, was easily synthesized and purified by sublimation. Thermogravimetric analysis showed single step volatilization with an onset temperature of 150 °C and negligible residual mass. Three temperature intervals with self-limiting growth were observed when depositing GaN films. In the second growth interval, the films were found to be near stoichiometric with very low levels of impurities and epitaxial orientation on 4H-SiC without an AlN seed layer. The films grown at 350 °C were found to be smooth with a sharp interface between the substrate and film. The bandgap of these films was 3.41 eV with the Fermi level at 1.90 eV, showing that the GaN films were unintentionally n-type doped. This new triazenide precursor enables ALD of GaN for semiconductor applications and provides a new Ga(III) precursor for future deposition processes.
Juvenile systemic sclerosis (JSSc) is a rare disease of childhood and currently no international consensus exists with regard to its assessment and treatment. This SHARE (Single Hub and Access point for paediatric Rheumatology in Europe) initiative, based on expert opinion informed by the best available evidence, provides recommendations for the assessment and treatment of patients with JSSc with a view to improving their outcome. Experts focused attention not only on the skin assessment but also on the early signs of internal organ involvement whose proper treatment can significantly affect the long-term outcome. A score for disease severity is proposed in order to perform a structured assessment of outcome over time but a validation in a wider patient population is recommended. Finally, a stepwise treatment approach is proposed in order to unify the standard of care throughout Europe with the aim to reduce morbidity and mortality in this disease.
Quality of measurement results and their accuracy in not neccessary to be high in conventional systems, approximate results are enough to know exactly what happens in the system. However, with increased penetration of renewable sources in the grid, need for high quality and precise measurements has risen. In order to have precise information about power quality, good knowledge of the behaviour of power quality analyzers is needed. Good knowledge can only be obtained by calibration of those meters. This paper describes start of development of a fully traceable power quality reference setup for the calibration of power quality analyzers based on digital sampling of voltage/current signals, and shown preliminary results.
This paper presents a laboratory setup for testing and experimental verification of fault detection methods based on contactless measurement of power line magnetic field. The setup consists of a physical power line model scaled to laboratory conditions with two orthogonal measuring coils installed on one support pole underneath phase conductors. Voltages induced in the coils are amplified and filtered out by using analog electrical circuits and are fed to a digital data acquisition board. The sampled voltages are digitally processed by employing a generalized fault detection method previously developed by the authors. In this paper the main steps for designing the measuring coils, analog amplifying and filtering circuits are described in detail. The developed laboratory setup is verified by experiments for different shunt and series faults.
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