Numerical Models Of The Early Stages Of Planet Formation - A New Perspective On The Role Of Turbulence
In the earliest stages of planet formation micrometer-sized dust grains collide and gradually build up kilometer-sized planetesimals, bodies that are so large that they can attract each other directly by gravity. This is an important landmark on the way to real planets because of the change to gravity-dominated growth. The road from boulders to planetesimals is however poorly known. Boulders have poor sticking properties and spiral into the young star due to the head wind from the slower rotating gas. This work presents the first detailed computer simulations of the motion of dust and boulders in turbulent protoplanetary discs. The turbulent diffusion coefficient of small dust grains is measured to be surprisingly high, whereas larger boulders concentrate by up to two orders of magnitude in transient high pressure regions that arise spontaneously in magnetorotational turbulence. The coupled motion of boulders and gas is found to be linearly unstable to the so-called streaming instability, leading to a turbulent state that is characterised by dense clumps of boulders that shield each other against the head wind of the gas.
Theatre in London has celebrated a rich and influential history, and in 1976 the first volume of J. P. Wearing's reference series provided researchers with an indispensable resource of these productions. In the decades since the original calendars were produced, several research aids have become available, notably various reference works and the digitization of important newspapers and relevant periodicals. The second edition of The London Stage 1930-1939: A Calendar of Productions, Performers, and Personnel provides a chronological calendar of London shows from the first of January, 1930, through the 31st of December, 1939. The volume chronicles more than 4,250 productions at 61 major central London theatres during this period. For each production the following information is provided: *Title *Author *Theatre *Performers *Personnel *Opening and Closing Dates *Number of Performances Other details include genre of the production, number of acts, and a list of reviews. A comment section includes other interesting information, such as plot description, first-night reception by the audience, noteworthy performances, staging elements, and details of performances in New York either prior to or after the London production. Among the plays staged in London during this decade were The Barretts of Wimpole Street, French without Tears, George and Margaret, The Greeks Had a Word for It, Laburnum Grove, Lady Precious Stream, The Late Christopher Bean, Love on the Dole, Me and My Girl, Private Lives, and 1066 and All That, as well as numerous musical comedies (British and American), foreign works, operas, ballets, and revivals of English classics. A definitive resource, this edition revises, corrects, and expands the original calendar. In addition, approximately 20 percent of the material-in particular, information of adaptations and translations, plot sources, and comment information-is new. Arranged chronologically, the shows are fully indexed by title, genre, and theatre. A general index includes numerous subject entries on such topics as acting, audiences, censorship, costumes, managers, performers, prompters, staging, and ticket prices. The London Stage 1930-1939 will be of value to scholars, theatrical personnel, librarians, writers, journalists, and historians.
Not a Stage! is written for teachers, students, and scholars interested in the academic, social, and emotional needs of young adolescents. It is unique because it actively resists basing the practice, research, and theory of young adolescent education on developmentalism and the developmental stage of young adolescence. The purpose of this book is to begin to reorient the discourse on young adolescent growth and change and in turn reconceptualize the education of young adolescents. The book infuses a contingent, recursive conception of adolescent growth and change into the discourse around young adolescence by making three pleas to those interested in the schooling of young adolescents: to move away from a developmentally responsive vision to a contingently and recursively relational vision; to move from characterizing young adolescence to particularizing young adolescents; and to move from a sameness curriculum to a difference curriculum.