Book Excerpt: \u3cem\u3eThe Guns of Normandy: A Soldier’s Eye View of France\u3c/em\u3e

Editor’s Note: Everyone who studies the land battles of the Second World War knows that artillery was the principle weapon employed by the Allied armies, but the gunners rarely receive the attention they deserve in narratives of the campaign. George Blackburn has written a book, The Guns of Normandy which restores the gunners to their rightful place. CMH is proud to publish two chapters from this book to announce that our Autumn issue will include an excerption from Mr. Blackburn’s forthcoming sequel. Chapter 15 takes up the story on 12 July 1944 as 4th Field Regiment is committed to support 4th Canadian Infantry Brigade west of Caen

Nonlinear Breit-Wheeler pair creation with bremsstrahlung γ\gamma rays

Electron-positron pairs are produced through the Breit-Wheeler process when energetic photons traverse electromagnetic fields of sufficient strength. Here we consider a possible experimental geometry for observation of pair creation in the highly nonlinear regime, in which bremsstrahlung of an ultrarelativistic electron beam in a high-$Z$ target is used to produce $\gamma$ rays that collide with a counterpropagating laser pulse. We show how the target thickness may be chosen to optimize the yield of Breit-Wheeler positrons, and verify our analytical predictions with simulations of the cascade in the material and in the laser pulse. The electron beam energy and laser intensity required are well within the capability of today's high-intensity laser facilities.Comment: 12 pages, 5 figure

Arthur Cotton and Irrigation in Tasmania, 1839-43

Cotton, an officer of the East India Company with experience of irrigation, visited Tasmania for periods totalling three years. His influence was important in gaining acceptance of irrigation as an aid to cereal production and the livestock industry. Details are given of his Tasmanian work, which had particular significance there for its emphasis on water conservation

Low energy electron scattering from DNA and RNA bases: shape resonances and radiation damage

Calculations are carried out to determine elastic scattering cross sections and resonance energies for low energy electron impact on uracil and on each of the DNA bases (thymine, cytosine, adenine, guanine), for isolated molecules in their equilibrium geometry. Our calculations are compared with available theory and experiment. We also attempt to correlate this information with experimental dissociation patterns through an analysis of the temporary anion structures that are formed by electron capture in shape resonances.Comment: 20 pages, 12 figures, submitted to J. Chem. Phy

Content Based Retrieval and Navigation of Music

Contents 1 Introduction ................................................... 3 2 Literature Review .............................................. 4 2.1 Navigation ............................................... 4 2.2 Navigation of audio ........................................ 4 2.3 Contentrepresentations ..................................... 5 2.3.1 The musical score ................................... 6 2.3.2 Performance data .................................... 6 2.3.3 Musical pitch contours ................................ 6 2.3.4 Alternative representations ............................ 7 2.3.5 The Fourier transform ................................ 7 2.4 Content based retrieval ..................................... 8 2.4.1 Retrieval of digital audio samples ....................... 8 2.4.2 Query by humming .................................. 8 2.4.3 Lemstrm and Laine ................................. 9 2.4.4 Image matching techni