Interplay between valence and core excitation mechanisms in the breakup of halo nuclei

The phenomenon of core excitation in the breakup of a two-body halo nucleus is investigated. We show that this effect plays a significant role in the reaction dynamics and, furthermore, its interference with the valence excitation mechanism has sizable and measurable effects on the breakup angular distributions. These effects have been studied in the resonant breakup of 11Be on a carbon target, populating the resonances at 1.78 MeV (5/2+) and 3.41 MeV (3/2+). The calculations have been performed using a recently extension of the DWBA method, which takes into account the effect of core excitation in both the structure of the halo nucleus and in the reaction mechanism. The calculated angular distributions have been compared with the available data [Fukuda et al., Phys. Rev. C70,054606]. Although each of these resonances is dominated by one of the two considered mechanisms, the angular patterns of these resonances depend in a very delicate way on the interference between them. This is the first clear evidence of this effect but the phenomenon is likely to occur in other similar reactions.Comment: 5 pages, 2 figures, (Version to appear in Physical Review Letters

Deep mantle structure and the postperovskite phase transition

Seismologists have known for many years that the lowermost mantle of the Earth is complex. Models based on observed seismic phases sampling this region include relatively sharp horizontal discontinuities with strong zones of anisotropy, nearly vertical contrasts in structure, and small pockets of ultralow velocity zones (ULVZs). This diversity of structures is beginning to be understood in terms of geodynamics and mineral physics, with dense partial melts causing the ULVZs and a postperovskite solid–solid phase transition producing regional layering, with the possibility of large-scale variations in chemistry. This strong heterogeneity has significant implications on heat transport out of core, the evolution of the magnetic field, and magnetic field polarity reversals

Determining B(E1)B(E1) distributions of weakly bound nuclei from breakup cross sections using Continuum Discretized Coupled Channels calculations. Application to 11^{11}Be

A novel method to extract the $B(E1)$ strength of a weakly bound nucleus from experimental Coulomb dissociation data is proposed. The method makes use of continuum discretized coupled channels (CDCC) calculations, in which both nuclear and Coulomb forces are taken into account to all orders. This is a crucial advantage with respect to the standard procedure based on the Equivalent Photon Method (EPM) which does not properly take into account nuclear distortion, higher order coupling effects, or Coulomb-nuclear interference terms. The procedure is applied to the $^{11}$Be nucleus using two sets of available experimental data at different energies, for which seemingly incompatible $B(E1)$ have been reported using the EPM. We show that the present procedure gives consistent $B(E1)$ strengths, thus solving the aforementioned long-standing discrepancy between the two measurements.Comment: Submitted for publicatio

Seismological support for the metastable superplume model, sharp features, and phase changes within the lower mantle

Recently, a metastable thermal-chemical convection model was proposed to explain the African Superplume. Its bulk tabular shape remains relatively stable while its interior undergoes significant stirring with low-velocity conduits along its edges and down-welling near the middle. Here, we perform a mapping of chemistry and temperature into P and S velocity variations and replace a seismically derived structure with this hybrid model. Synthetic seismogram sections generated for this 2D model are then compared directly with corresponding seismic observations of P (P, PCP, and PKP) and S (S, SCS, and SKS) phases. These results explain the anticorrelation between the bulk velocity and shear velocity and the sharpness and level of SKS travel time delays. In addition, we present evidence for the existence of a D" triplication (a putative phase change) beneath the down-welling structure

Innovative Service-Based Business Concepts for the Machine Tool Building Industry

Organised by: Cranfield UniversityDuring the last decade, machine tool building companies have been forced to put innovative offers on the market. Due to the technical features of their products and the prevailing organizational structures in this sector, especially product-service systems are a promising way of creating a unique selling point. In this paper, potential new business concepts for machine tool builders will be presented which aim at fulfilling basic customer needs like the increase in quality, flexibility, productivity and the reduction of lead times, costs and risks. For the implementation of these product-service systems, practical examples are given.Mori Seiki – The Machine Tool Compan

Filmmaking as a Practice in Critical Theory

This multi-part project pulls together all my fields of research under the umbrella of my ultimate interest– agriculture and its future. The film portion focuses on regional and seasonal agriculture in Southern Germany near Lake Constance. It focuses on several families who do small-scale agricultural production utilizing various methods but ultimately touches on our current disconnect from our food systems and nature. The written portion found in this document focuses on filmmaking as a practice in critical theory, a tool to visualize what written theory cannot. Filming happened over a three-week period in Summer 2021for the portion shot in Germany. The research for the written portion on film involved watching all available films from Fredi M. Murer and Wim Wenders, choosing a few from each and detailing the involvement of theory. I was not a filmmaker when I began this project, so much of this endeavor has been trial and error with many changes being made to the scope and intention of the project over the last year. I see this as only the beginning and intend to make a longer version of this film with more interviews, including some here in the US, to show the dichotomy between capitalist systems and the growing disconnect from our food. The longer version will be more essayistic in style, with my voice being more apparent as I grow in my filmmaking abilities. For now, though, this version of the project is a culmination of all my areas of interest and doesn\u27t seek to prove anything, rather hopes to impact the way people think about film and agriculture

Ag on Ge(111): 2D X-ray structure analysis of the (Wurzel)3 x (Wurzel)3 superstructure

We have studied the Ag/Ge(111)(Wurzel)3 x (Wurzel)3 superstructure by grazing-incidence X-ray diffraction. In our structural analysis we find striking similarities to the geometry of Au on Si(111). The Ag atoms form trimer clusters with an Ag-Ag distance of 2.94+-0.04°A with the centers of the trimers being located at the origins of the (Wurzel)3 x (Wurzel)3 lattice. The Ag layer is incomplete and at least one substrate layer is distorted

Automatic identification of gait events using an instrumented sock

Background: textile-based transducers are an emerging technology in which piezo-resistive properties of materials are used to measure an applied strain. By incorporating these sensors into a sock, this technology offers the potential to detect critical events during the stance phase of the gait cycle. This could prove useful in several applications, such as functional electrical stimulation (FES) systems to assist gait. Methods: we investigated the output of a knitted resistive strain sensor during walking and sought to determine the degree of similarity between the sensor output and the ankle angle in the sagittal plane. In addition, we investigated whether it would be possible to predict three key gait events, heel strike, heel lift and toe off, with a relatively straight-forward algorithm. This worked by predicting gait events to occur at fixed time offsets from specific peaks in the sensor signal. Results: our results showed that, for all subjects, the sensor output exhibited the same general characteristics as the ankle joint angle. However, there were large between-subjects differences in the degree of similarity between the two curves. Despite this variability, it was possible to accurately predict gait events using a simple algorithm. This algorithm displayed high levels of trial-to-trial repeatability. Conclusions: this study demonstrates the potential of using textile-based transducers in future devices that provide active gait assistance

Germanene: a novel two-dimensional Germanium allotrope akin to Graphene and Silicene

Using a gold (111) surface as a substrate we have grown in situ by molecular beam epitaxy an atom-thin, ordered, two-dimensional multi-phase film. Its growth bears strong similarity with the formation of silicene layers on silver (111) templates. One of the phases, forming large domains, as observed in Scanning Tunneling Microscopy, shows a clear, nearly flat, honeycomb structure. Thanks to thorough synchrotron radiation core-level spectroscopy measurements and advanced Density Functional Theory calculations we can identify it to a $\sqrt{3}$x$\sqrt{3}$R(30{\deg}) germanene layer in coincidence with a $\sqrt{7}$x$\sqrt{7}$R(19.1{\deg}) Au(111) supercell, thence, presenting the first compelling evidence of the birth of a novel synthetic germanium-based cousin of graphene.Comment: 16 pages, 4 figures, 1 tabl