Surface integrity in metal machining - Part I: Fundamentals of surface characteristics and formation mechanisms

The surface integrity of machined metal components is critical to their in-service functionality, longevity and overall performance. Surface defects induced by machining operations vary from the nano to macro scale, which cause microstructural, mechanical and chemical effects. Hence, they require advanced evaluation and post processing techniques. While surface integrity varies significantly across the range of machining processes, this paper explores the state-of-the-art of surface integrity research with an emphasis on their governing mechanisms and emerging evaluation approaches. In this review, removal mechanisms are grouped by their primary energy transfer mechanisms; mechanical, thermal and chemical based. Accordingly, the resultant multi-scale phenomena associated with metal machining are analyzed. The contribution of these material removal mechanisms to the workpiece surfaces/subsurface characteristics is reviewed. Post-processing options for the mitigation of induced surface defects are also discussed

Evidence for reduced collectivity around the neutron mid-shell in the stable even-mass Sn isotopes from new lifetime measurements

Precise measurements of the lifetimes of the first excited 2+ states in the stable even-A Sn isotopes 112-124Sn have been performed using the Doppler shift attenuation technique. For the isotopes 112Sn, 114Sn and 116Sn the E2 transition strengths deduced from the measured lifetimes are in disagreement with the previously reported values and indicate a shallow minimum at N=66. The observed deviation from a maximum at mid-shell is attributed to the obstructive effect of the s1/2 neutron orbital in generating collectivity when near the Fermi level. © 2010 Elsevier B.V.Financial support from the Spanish Ministerio de Ciencia e Innovaci on under contracts FPA2007-66069, FPA2009-13377-C02-01 and FPA2009-13377-C02-02, the Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007-00042) and the Australian Re- search Council Discovery Scheme, grant no. DP0773273Peer Reviewe

Evidence for reduced collectivity around the neutron mid-shell in the stable even-mass Sn isotopes from new lifetime measurements

Precise measurements of the lifetimes of the first excited 2+ states in the stable even-A Sn isotopes 112-124Sn have been performed using the Doppler shift attenuation technique. For the isotopes 112Sn, 114Sn and 116Sn the E2 transition strengths deduced from the measured lifetimes are in disagreement with the previously reported values and indicate a shallow minimum at N=66. The observed deviation from a maximum at mid-shell is attributed to the obstructive effect of the s1/2 neutron orbital in generating collectivity when near the Fermi level. © 2010 Elsevier B.V.Financial support from the Spanish Ministerio de Ciencia e Innovaci on under contracts FPA2007-66069, FPA2009-13377-C02-01 and FPA2009-13377-C02-02, the Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007-00042) and the Australian Re- search Council Discovery Scheme, grant no. DP0773273Peer Reviewe

New lifetime measurements in the stable semimagic Sn isotopes using the Doppler-shift attenuation technique.

Precise measurements of lifetimes in the picosecond range of excited states in the stable even-A Sn isotopes 112;114;116;122 Sn have been performed using the Doppler shift attenuation technique. For the rst excited 2 + states in 112 Sn, 114 Sn and 116 Sn the E2 transition strengths deduced from the measured lifetimes are in disagreement with the previously adopted values. They indicate a shallow minimum at N = 66 in contrast to the maximum at mid-shell predicted by modern shell model calculations.Financial support from the Spanish Ministerio de Ciencia e Innovaci on under contracts FPA2007-66069 and FPA2009-13377-C02-02, and the Australian Research Council Discovery Scheme, grant no. DP0773273.Peer Reviewe

L’India nella musica e nella cultura pop. Cronologia di un’utopia transculturale

L'influsso della cultura e delle tradizioni musicali indiane sulla musica afroamericana e sulla popular music degli anni Cinquanta-Sessanta del XX secolo ha prodotto numerose esperienze di interculturalità, fallendo però quasi sempre i propri obiettivi sul piano della transculturalità. Il fenomeno viene storicizzato a partire dalla ricostruzione delle influenze diffuse dai grandi divulgatori del pensiero e della musica indostana nel Novecento euroamericano, e degli incontri, anche personali, tra maestri indiani come Ravi Shankar e artisti europei e afroamericani come i Beatles e John Coltrane