Horizontal saddle-supported storage vessels: Theoretical and experimental comparisons of plastic collapse loads

Previous experimental work (1) on cylindrical vessels supported at the ends and subjected to central loading indicated that different collapse mechanisms could occur when the loading is applied either through loosely fitted saddles or through welded saddles. The modes of failure are dependent upon the value of the R/t ratio of the vessel. In general, progressive plastic collapse occurs in vessels with low values of R/t ratio, typically less than 200, and elastic-plastic buckling is observed in vessels with higher R/t ratios. The aim of this paper is to examine various theoretical analyses for plastic collapse loads, applicable to vessels with low values of R/t ratio, and compare these with the experimental results obtained by the authors and others. The theoretical behaviour appropriate for the thinner vessels, where the mode is failure is by buckling, has been previously examined by the authors elsewhere (2) although all the experimental values are included here for completeness. A number of classical and numerical analytical methods are employed to obtain the plastic collapse loads. Comparisons with the experimental results show that the elastic-plastic finite element analysis gives the best agreement. Further work in the form of a parametric study has been conducted on a range of vessels to enable a design method to be established. This is published as a companion paper in this volume

Horizontal saddle-supported storage vessels: A parametric study of plastic collapse loads

Previous work by the present authors compared various theoretical methods with simple experiments for the plastic collapse load on end supported vessels loaded centrally by rigid saddles. It was found that the best agreement was obtained by using an elastic-plastic finite element analysis approach. In the present paper the elastic-plastic method has been used to examine the effect of various geometric parameters on the collapse load. A symmetrical model which replicated the geometric features of the experiments can be used to give an indication of the effect of specific isolated geometric variables but for others and for the purposes of undertaking a full parametric survey the model was modified to reflect an actual twin saddle supported vessel

PO-0698: Clinical outcomes of 4D CBCT-guided stereotactic body radiotherapy for inoperable hepatocellular carcinomas

Poster: Clinical track: Gastrointestinal tumours (upper and lower GI)published_or_final_version3rd ESTRO Forum, Barcelona, Spain, 24-28 April 2015. In Radiotherapy & Oncology, 2015, v. 115, p. S342-S34

Neural Signals of Video Advertisement Liking:Insights into Psychological Processes and their Temporal Dynamics

What drives the liking of video advertisements? The authors analyzed neural signals during ad exposure from three functional magnetic resonance imaging (fMRI) data sets (113 participants from two countries watching 85 video ads) with automated meta-analytic decoding (Neurosynth). These brain-based measures of psychological processes—including perception and language (information processing), executive function and memory (cognitive functions), and social cognition and emotion (social-affective response)—predicted subsequent self-report ad liking, with emotion and memory being the earliest predictorsafter the first three seconds. Over the span of ad exposure, while the predictiveness of emotion peaked early and fell, that of social cognition had a peak-and-stable pattern, followed by a late peak of predictiveness in perception and executive function.At the aggregate level, neural signals—especially those associated with social-affective response—improved the prediction of out-of-sample ad liking compared with traditional anatomically based neuroimaging analysis and self-report liking. Finally, earlyonset social-affective response predicted population ad liking in a behavioral replication. Overall, this study helps delineate the psychological mechanisms underlying ad processing and ad liking and proposes a novel neuroscience-based approach for generating psychological insights and improving out-of-sample predictions

Schizotypy as an organizing framework for social and affective sciences

Schizotypy, defined in terms of commonly occurring personality traits related to the schizophrenia spectrum, has been an important construct for understanding the neurodevelopment and stress-diathesis of schizophrenia. However, as schizotypy nears its sixth decade of application, it is important to acknowledge its impressively rich literature accumulating outside of schizophrenia research. In this article, we make the case that schizotypy has considerable potential as a conceptual framework for understanding individual differences in affective and social functions beyond those directly involved in schizophrenia spectrum pathology. This case is predicated on (a) a burgeoning literature noting anomalies in a wide range of social functioning, affiliative, positive and negative emotional, expressive, and social cognitive systems, (b) practical and methodological features associated with schizotypy research that help facilitate empirical investigation, and (c) close ties to theoretical constructs of central importance to affective and social science (eg, stress diathesis, neural compensation). We highlight recent schizotypy research, ie providing insight into the nature of affective and social systems more generally. This includes current efforts to clarify the neurodevelopmental, neurobiological, and psychological underpinnings of affiliative drives, hedonic capacity, social cognition, and stress responsivity systems. Additionally, we discuss neural compensatory and resilience factors that may mitigate the expression of stress-diathesis and functional outcome, and highlight schizotypy's potential role for understanding cultural determinants of social and affective functions

Schwinger type processes via branes and their gravity duals

We consider Schwinger type processes involving the creation of the charge and monopole pairs in the external fields and propose interpretation of these processes via corresponding brane configurations in Type IIB string theory. We suggest simple description of some new interesting nonperturbative processes like monopole/dyon transitions in the electric field and W-boson decay in the magnetic field using the brane language. Nonperturbative pair production in the strong coupling regime using the AdS/CFT correspondence is studied. The treatment of the similar processes in the noncommutative theories when noncommutativity is traded for the background fields is presented and the possible role of the critical magnetic field which is S-dual to the critical electric field is discussed.Comment: 29pp, LaTeX; v3. reference adde

Implementation of an Optimal First-Order Method for Strongly Convex Total Variation Regularization

We present a practical implementation of an optimal first-order method, due to Nesterov, for large-scale total variation regularization in tomographic reconstruction, image deblurring, etc. The algorithm applies to $\mu$-strongly convex objective functions with $L$-Lipschitz continuous gradient. In the framework of Nesterov both $\mu$ and $L$ are assumed known -- an assumption that is seldom satisfied in practice. We propose to incorporate mechanisms to estimate locally sufficient $\mu$ and $L$ during the iterations. The mechanisms also allow for the application to non-strongly convex functions. We discuss the iteration complexity of several first-order methods, including the proposed algorithm, and we use a 3D tomography problem to compare the performance of these methods. The results show that for ill-conditioned problems solved to high accuracy, the proposed method significantly outperforms state-of-the-art first-order methods, as also suggested by theoretical results.Comment: 23 pages, 4 figure

Evolutionary Responses of a Reef-building Coral to Climate Change at the End of the Last Glacial Maximum

Climate change threatens the survival of coral reefs on a global scale, primarily through mass bleaching and mortality as a result of marine heatwaves. While these short-term effects are clear, predicting the fate of coral reefs over the coming century is a major challenge. One way to understand the longer-term effect of rapid climate change is to examine the response of coral populations to past climate shifts. Coastal and shallow-water marine ecosystems such as coral reefs have been reshaped many times by sea-level changes during the Pleistocene, yet few studies have directly linked this with its consequences on population demographics, dispersal, and adaptation. Here we use powerful analytical techniques, afforded by haplotype-phased whole-genomes, to establish such links for the reef-building coral, Acropora digitifera. We show that three genetically distinct populations are present in northwestern Australia, and that their rapid divergence since the last glacial maximum (LGM) can be explained by a combination of founder-effects and restricted gene flow. Signatures of selective sweeps, too strong to be explained by demographic history, are present in all three populations and overlap with genes that show different patterns of functional enrichment between inshore and offshore habitats. In contrast to rapid divergence in the host, we find that photosymbiont communities are largely undifferentiated between corals from all three locations, spanning almost 1000 km, indicating that selection on host genes, and not acquisition of novel symbionts, has been the primary driver of adaptation for this species in northwestern Australia

Insulator-Superfluid transition of spin-1 bosons in an optical lattice in magnetic field

We study the insulator-superfluid transition of spin-1 bosons in an optical lattice in a uniform magnetic field. Based on a mean-field approximation we obtained a zero-temperature phase diagram. We found that depending on the particle number the transition for bosons with antiferromagnetic interaction may occur into different superfluid phases with spins aligned along or opposite to the field direction. This is qualitatively different from the field-free transition for which the mean-field theory predicts a unique (polar) superfluid state for any particle number.Comment: 10 pages, 2 eps figure