0000000000121699
AUTHOR
L. Zamora
Raman measurements on GaN thin films for PV - purposes
Raman scattering (RS) is a very important experimental tool to characterize the optical modes and another elementary excitations of materials. Among other issues it can determine for example the degree of crystalline quality and point defects like local modes. Therefore GaN - thin films and related compounds for photovoltaic purposes and as processed by several systems have been measured by this technique. The films were grown by Molecular Beam Epitaxy (MBE), Close Spaced Vapor Transport (CSVT) and Laser Ablation (LA) with the use of optimal growth parameters and substrates. Gallium nitride crystallizes in the wurtzite structure with 4 atoms in the unit cell and presents 7 allowed Raman mod…
SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study
Abstract Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in su…
Climate change and human impact in central Spain during Roman times: High-resolution multi-proxy analysis of a tufa lake record (Somolinos, 1280m asl)
The Roman Period is considered a crucial phase in the evolution of Holocene landscapes, due to the coincidence of major climatic, environmental, economic and cultural changes. However, there is still debate as to the regional expression of these changes, and to the mechanisms involved, particularly in the topographically and climatically complex region of the Mediterranean. In order to improve our understanding of the synergies between societal and environmental change during this period in central Spain, we present a comprehensive case study based on the integration of multi-proxy palaeoenvironmental, archaeological and historical data. High-resolution, interdisciplinary research has been …