Africa at LSE blog 5th anniversary reading list: 10 must-read books on African politics, society and economics

6 June 2016 is the five year anniversary of the launch of the Africa at LSE blog. To celebrate the occasion, LSE Review of Books recommends ten illuminating reads on African politics, society and economics. You may also like to check out ten recommended Africa at LSE blog posts to revisit , covering diverse topics such as Africa’s urban transition, the question of penalty shoot-outs in football and Mahatma Gandhi’s political awakening in South Africa

Influence of a humidor on the aerodynamics of baseballs

We investigate whether storing baseballs in a controlled humidity environment significantly affects their aerodynamic properties. To do this, we measure the change in diameter and mass of baseballs as a function of relative humidity (RH) in which the balls are stored. We then model trajectories for pitched and batted baseballs to assess the difference between those stored at 30% RH versus 50% RH. The results show that a drier baseball may be expected to curve slightly more than a humidified one for a given pitch velocity. We also find that the aerodynamics alone would add ~2 feet to the distance a moister ball is hit. However, this is compensated by a ~6 foot reduction in batted distance due to the well known change in coefficient of restitution of the ball. We discuss consequences of these results for baseball played at Coors Field in Denver, where baseballs have been stored in a humidor at 50% RH since 2002.Comment: 21 pages, 7 figures, modified and re-posted 2/2

HPC for improved efficiency on standard machine tools by using new fluid-driven spindles

Part of: Seliger, Günther (Ed.): Innovative solutions : proceedings / 11th Global Conference on Sustainable Manufacturing, Berlin, Germany, 23rd - 25th September, 2013. - Berlin: Universitätsverlag der TU Berlin, 2013. - ISBN 978-3-7983-2609-5 (online). - http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-40276. - pp. 241-246.The use of fluid-driven spindles is well known for machining various components, but not in real metal cutting. Machining of larger precision components as prototypes, tools and dies requires the use of relatively large machine tools and high-performance spindles. Usually these are mechanical spindles with relatively high power, displaying a rather low maximum speed of approximately 15,000 rpm. However, in semi-finishing and finishing with HPC conditions and in micro machining, the required rotation speeds are higher and the required power is lower. This paper presents sustainability and efficiency using fluid-driven spindles for HPC on standard machine tools with small tool diameters and rotation speeds of up to 90,000 rpm using air and 30,000 rpm using the coolant flow. The fluid-driven spindle leads to a significant widening of the application range of larger machine tools and to an improvement of productivity by higher efficiency and faster tool- and spindle change, respectively

Predatory Publishing

The ‘predatory publishing’ label is often linked to open access in order to discredit it, evoking as this concept does both vanity and self-publishing. Today, however, more and more critical attention is being paid to how this label has been and is still being constructed. On the one hand, the rise of unscrupulous OA publishers who charge author-facing fees and provide little to no editorial oversight is indicative of the increasing pressure placed on scholars to produce more and more research “outputs” and to increase the citability and indexing of such. Fuelled by various national incentive systems, it is a pressure that can lead to serious violations of traditional publishing ethics: by authors who self-publish or self-plagiarise in order to meet their targets, and by a certain breed of journals that seem more concerned with making a pro t than with disseminating academic knowledge, as shown in the essays in this pamphlet by Vaclav Stetka and by Luděk Brož, Tereza Stöckelová, and Filip Vostal, especially relative to the notorious case of Czech scholar Wadim Stielkowski, who at one point boasted of having published 17 monographs and 60 articles in just 3 years and who, even after departing Charles University, Prague under a hail of scandal, continues to teach and publish. Stielkowski’s “case,” as it were, for which one of the contributors to this volume, Vaclav Stetka, served as chief whistleblower, serves as a somewhat spectacular exemplum of what can happen when two malevolent forces converge: a dishonest scholar hellbent on maximizing their publications and citations and fraudulent, for-profit “fake journals.” On the other hand, do we need to be careful when it comes to accusing all those labelled as predatory publishers as being driven exclusively by profit? After all, much the same can be said about commercial publishers such as Elsevier who are perceived to be legitimate if not, indeed, prestigious