Regularized numerical integration of multibody dynamics with the generalized alpha method*

This paper discusses the consistent regularization property of the generalized α method when applied as an integrator to an initial value high index and singular differential-algebraic equation model of a multibody system. The regularization comes from within the discretization itself and the discretization remains consistent over the range of values the regularization parameter may take. The regularization involves increase of the smallest singular values of the ill-conditioned Jacobian of the discretization and is different from Baumgarte and similar techniques which tend to be inconsistent for poor choice of regularization parameter. This regularization also helps where pre-conditioning the Jacobian by scaling is of limited effect, for example, when the scleronomic constraints contain multiple closed loops or singular configuration or when high index path constraints are present. The feed-forward control in Kane's equation models is additionally considered in the numerical examples to illustrate the effect of regularization. The discretization presented in this work is adopted to the first order DAE system (unlike the original method which is intended for second order systems) for its A-stability and same order of accuracy for positions and velocities.

A simple biosynthetic method for the preparation of glycerol-labelled phosphatidylcholine

A convenient method is described for the preparation of glycerol-labelled phosphatidylcholine with very high specific activity. It involves germination of soybean seeds in the dark at 37°C for 48 h in the presence of labelled glycerol, followed by extraction and purification of the phospholipid.

Leading Beautifully : Educational Leadership as Connoisseurship

Leading Beautifully provides a new dimension to understanding effective leadership. Drawing from lessons in the arts and the humanities, English and Ehrich explore how educational decision-making in schools can be informed by identity, personal competence, and an understanding of the field's intellectual foundations. Based on in-depth interviews of artists and educational leaders, this book provides insight into the inner world of successful leaders who have developed competencies and understandings that extend beyond the standard leadership tool box. This exciting new book explores the theory and practice of leadership connoisseurship as a human-centered endeavor and as an antidote to mechanistic, business-oriented practices. The authors' well-grounded reconsideration of educational leadership will enliven and enhance any educational leader's practice.