An Observational Overview of Solar Flares

We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe

Financial management in the Marine Corps: an evaluation

A new assignment or mission for any Marine has traditionally been a source of challenge. Since 1776, such opportunities have provided a medium for greater service to both his country and his corps. Therefore, naturally and almost inevitably, this was the mental response of our group of four Marine officers when the first term project for the Research Seminar in Comptrollership was assigned. Military breeding and esprit dictated that our efforts, regardless of ultimate value, must be directed toward an objective that might prove beneficial, in some small measure, to our corps instead of merely attempting mechanically to satisfy an imposed academic requirement.http://www.archive.org/details/financialmanagem00wilcU.S. Marine Corps (U.S.M.C.) authors

Numerical Investigation of Dual Bell Nozzle Flow Field

The flow field of a cold flow dual bell has been numerically simulated with the DLR TAU code. The two operation modes and the transition from one mode to the other are investigated by varying the nozzle pressure ratio. A cold flow test campaign on a sub-scale nozzle model yields experimental data for validation of the simulation. Pressure measurements along the nozzle wall and schlieren optics provides information on the flow field in the nozzle. In addition, the models have been successively shortened to allow the observation of the shock system in the vicinity of the contour inflection