Simulation of Wrinkle Formation in Free Electromagnetic Tube Compression

A 3-dimensional (3D) finite element (FE) simulation of free electromagnetic (EM) tube compression was performed with the aim of predicting wrinkle formation. Staggered coupling was applied between the EM and mechanical parts of the problem. The full 360° portion of the problem was modelled since the wrinkle formation does not represent any symmetry in circumferential direction. The initial geometric imperfections of the tube were measured and included in the model to trigger buckling. The deformed geometry with the wrinkles could be predicted accurately

Avoiding Bending in Case of Uniaxial Tension with Electromagnetic Forming

During electromagnetic forming, excessive bending of the specimen takes place due to high velocities and inertia. We show that the excessive bending can be prevented by optimizing the coil geometry in case of uniaxial tension. The process is simulated with various coil geometries, and the resulting amount of bending is compared to the case of standard Nakajima Test. The comparison shows that the bending can be minimised to acceptable levels to be able to call the method a decent way of determining forming limits. The results should be verified experimentally

Localized plasmon-engineered spontaneous emission of CdSe/ZnS nanocrystals closely-packed in the proximity of Ag nanoisland films for controlling emission linewidth, peak, and intensity

Cataloged from PDF version of article.Using metallic nanoislands, we demonstrate the localized plasmonic control and modification of the spontaneous emission from closely-packed nanocrystal emitters, leading to significant changes in their collective emission characteristics tuned spectrally and spatially by plasmon coupling. Using randomly-distributed silver nanoislands, we show that the emission linewidth of proximal CdSe/ZnS core-shell quantum dots is reduced by 22% and their peak emission wavelength is shifted by 14nm, while their ensemble photoluminescence is enhanced via radiative energy transfer by 21.6 and 15.1 times compared to the control groups of CdSe/ZnS nanocrystals with identical nano-silver but no dielectric spacer and the same nanocrystals alone, respectively. (C) 2007 Optical Society of America

Information-Theoretic Active Learning for Content-Based Image Retrieval

We propose Information-Theoretic Active Learning (ITAL), a novel batch-mode active learning method for binary classification, and apply it for acquiring meaningful user feedback in the context of content-based image retrieval. Instead of combining different heuristics such as uncertainty, diversity, or density, our method is based on maximizing the mutual information between the predicted relevance of the images and the expected user feedback regarding the selected batch. We propose suitable approximations to this computationally demanding problem and also integrate an explicit model of user behavior that accounts for possible incorrect labels and unnameable instances. Furthermore, our approach does not only take the structure of the data but also the expected model output change caused by the user feedback into account. In contrast to other methods, ITAL turns out to be highly flexible and provides state-of-the-art performance across various datasets, such as MIRFLICKR and ImageNet.Comment: GCPR 2018 paper (14 pages text + 2 pages references + 6 pages appendix

Spatially Selective Assembly of Quantum Dot Light Emitters in an LED Using Engineered Peptides

Cataloged from PDF version of article.Semiconductor nanocrystal quantum dots are utilized in numerous applications in nano- and biotechnology. In device applications, where several different material components are involved, quantum dots typically need to be assembled at explicit locations for enhanced functionality. Conventional approaches cannot meet these requirements where assembly of nanocrystals is usually material-nonspecific, thereby limiting the control of their spatial distribution. Here we demonstrate directed self-assembly of quantum dot emitters at material-specific locations in a color-conversion LED containing several material components including a metal, a dielectric, and a semiconductor. We achieve a spatially selective immobilization of quantum dot emitters by using the unique material selectivity characteristics provided by the engineered solid-binding peptides as smart linkers. Peptide-decorated quantum dots exhibited several orders of magnitude higher photoluminescence compared to the control groups, thus, potentially opening up novel ways to advance these photonic platforms in applications ranging from chemical to biodetection. © 2011 American Chemical Society

Integrating biological pathways and genomic profiles with ChiBE 2

Cataloged from PDF version of article.Background: Dynamic visual exploration of detailed pathway information can help researchers digest and interpret complex mechanisms and genomic datasets. Results: ChiBE is a free, open-source software tool for visualizing, querying, and analyzing human biological pathways in BioPAX format. The recently released version 2 can search for neighborhoods, paths between molecules, and common regulators/targets of molecules, on large integrated cellular networks in the Pathway Commons database as well as in local BioPAX models. Resulting networks can be automatically laid out for visualization using a graphically rich, process-centric notation. Profiling data from the cBioPortal for Cancer Genomics and expression data from the Gene Expression Omnibus can be overlaid on these networks. Conclusions: ChiBE's new capabilities are organized around a genomics-oriented workflow and offer a unique comprehensive pathway analysis solution for genomics researchers

Combined simulation of quasi-static deep drawing and electromagnetic forming by means of a coupled damage–viscoplasticity model at finite strains

The combination of quasi-static and electromagnetic pulse forming increases the formability of sheet metal forming processes. A cooperation between the institute of Applied Mechanics (IFAM) of the RWTH Aachen and the Institute of Forming Technology and Lightweight Construction (IUL) of the TU Dortmund is investigating these processes both experimentally and by simulation for the deep-drawing process of a cross-shaped cup. Aim of the work is to show and prove that with this forming strategy we obtain a more sharpened radius of the cup edges.The combined deformation process is simulated by means of finite elements using a material model developed in [1,2]. A recently proposed finite strain anisotropic viscoplastic model, taking combined nonlinear kinematic and isotropic hardening into account, is coupled with ductile damage in the context of continuum damage mechanics. For the simulation, the evolution equations for the internal variables of the constitutive model are numerically integrated in an explicit manner and the model is then implemented as a user material subroutine in the commercial finite element package LS-Dyna

ChiBE: interactive visualization and manipulation of BioPAX pathway models.

SUMMARY: Representing models of cellular processes or pathways in a graphically rich form facilitates interpretation of biological observations and generation of new hypotheses. Solving biological problems using large pathway datasets requires software that can combine data mapping, querying and visualization as well as providing access to diverse data resources on the Internet. ChiBE is an open source software application that features user-friendly multi-view display, navigation and manipulation of pathway models in BioPAX format. Pathway views are rendered in a feature-rich format, and may be laid out and edited with state-of-the-art visualization methods, including compound or nested structures for visualizing cellular compartments and molecular complexes. Users can easily query and visualize pathways through an integrated Pathway Commons query tool and analyze molecular profiles in pathway context. AVAILABILITY: http://www.bilkent.edu.tr/%7Ebcbi/chibe.html. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online