Evidence of relationship between strain and In-incorporation:Growth of N-polar In-rich InAlN buffer layer by OMCVD

International audienc

Inversion of asteroid photometry from

Context. Rotation properties (spin-axis direction and rotation period) and coarse shape models of asteroids can be reconstructed from their disk-integrated brightness when measured from various viewing geometries. These physical properties are essential for creating a global picture of structure and dynamical evolution of the main belt. Aims. The number of shape and spin models can be increased not only when new data are available, but also by combining independent data sets and inverting them together. Our aim was to derive new asteroid models by processing readily available photometry. Methods. We used asteroid photometry compiled in the Lowell Observatory photometry database with photometry from the Gaia Data Release 2. Both data sources are available for about 5400 asteroids. In the framework of the Asteroids@home distributed computing project, we applied the light curve inversion method to each asteroid to find its convex shape model and spin state that fits the observed photometry. Results. Due to the limited number of Gaia DR2 data points and poor photometric accuracy of Lowell data, we were able to derive unique models for only ∼1100 asteroids. Nevertheless, 762 of these are new models that significantly enlarge the current database of about 1600 asteroid models. Conclusions. Our results demonstrate the importance of a combined approach to inversion of asteroid photometry. While our models in general agree with those obtained by separate inversion of Lowell and Gaia data, the combined inversion is more robust, model parameters are more constrained, and unique models can be reconstructed in many cases when individual data sets alone are not sufficient

Elimination of the Leakage Inductance of the Primary Winding of an Impulse Transformer for a Contact-less Temperature Gauge

We continue in reconstruction of the temperature meter with optical transmission of temperature reading in the HF CVD reactor. The parasitic inductance causes degradation of the transformer. The issue is solved by including a non-dissipative snubber that recuperates the energy from the parasitic inductance back to the power supply and allows faster demagnetization, thereby improving the transfer of energy through the transformer to its secondary winding

Raman spectroscopy used to assess the temperature and mechanical stress in thin films of microelectronic structures

We are grateful to the scientific grant agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic for financial support of project VEGA No. 1/0947/16.In this experimental work we examined the temperature and mechanical stress in the thin films of microelectronic structures based on GaN and AlN by Raman spectroscopy. The rise in temperature in the Raman spectrum is shown by shifting the Raman bands toward lower wavenumbers. Similarly like with changes of temperature, the changes of the positions of Raman bands may indicate the changes of mechanical stress in the structure. It was confirmed experimentally that in the case of tensile stress the Raman bands are shifted towards lower wavenumbers, and under compressive stress to higher wavenumbers

Analysis of governance systems applied in multifunctional forest management in selected European mountain regions

The objective of this study is to map and analyse governance systems relevant for the implementation of multifunctional mountain forest management in selected European countries. This paper is based on the FP7 research project Advanced multifunctional forest management in European mountain ranges (ARANGE). Current governance systems relevant for the implementation of multifunctional forest management are analysed in seven case study areas the Iberian Mountains (Spain), Western Alps (France), Eastern Alps (Austria), Dinaric Mountains (Slovenia), Scandinavian Mountains (Sweden), Western Carpathians (Slovakia) and Western Rhodopes (Bulgaria). Qualitative social research methods were applied for data collection. Semi-structured questionnaire was focused on the following elements of governance participation and stakeholders interactions and inter-sectorial coordination. The results indicate that forest managers share a general perception of multifunctional forest management being focused on preserving or strengthening several forest functions and services including timber production. They believe that current governance systems basically support multifunctional management of mountain forests. The participatory and inter-sectoral processes are playing an important role in multifunctional forest management in selected European mountain regions. © by Zuzana Sarvašová 2015

Generation of hole gas in non-inverted InAl(Ga)N/GaN heterostructures

International audienceInAlN/GaN structures are grown using organometallic chemical vapor deposition at 730 °C. The sample for which the chamber cleaning step was applied after GaN growth shows a sharp In0.3Al0.7N/GaN transition, free electron density of ~2 × 1011 cm−2 and mobility of 44 cm2 V−1 s−1. On the other hand, the sample prepared without growth interruption demonstrated In0.4Al0.15Ga0.45N at the interface and compositional grading towards the In0.4Al0.6N surface. In this case a two-dimensional hole gas (2DHG) is created with a density of ~2 × 1012 cm−2 and mobility of ~0.6 cm2 V−1 s−1. Ga incorporation in the InAlN barrier is crucial for designing non-inverted 2DHG transistors