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Lee K.-A.,Andong National University | Jin Y.-M.,Andong National University | Sohn Y.-H.,Advanced Materials Processing and Analysis Center | Namkung J.,RIST | Kim M.-C.,RIST
Metals and Materials International | Year: 2011

This study tried to examine the suitability of strip casting processes such as PFC for soldering Au-Sn strips and to investigate changes in the microstructure and mechanical properties of the manufactured strips, following heat-treatment. Optimal production conditions were established for Au-20 %Sn strips and implemented to actually produce them. The inhomogeneous microstructure with indistinct phases that was present prior to heating was transformed into a homogeneous microstructure in which the continuous Au 5Sn phase surrounded the ìm-sized AuSn phases. Tensile results showed that the as-cast strip exhibited zero plasticity and a tensile strength of 338.3 MPa. After heating, the figure dropped somewhat while the plastic strain improved to 1.6%. As for the enhanced plasticity in the heat-treated strip, the continuous pattern of the ductile Au5Sn that surrounds the brittle AuSn was assumed to have caused plastic strain to take place on the boundaries of two phases, therefore resulting in the initiation and propagation of cracks. © KIM and Springer.

News Article
Site: www.materialstoday.com

ASM International (ASM), the world’s largest association of metals-focused materials professionals, has announced the election of Jon D Tirpak, as ASM’s 2015-2016 board of trustees president. Tirpak, who joined ASM in 1980, is ending a one-year term as vice president of the board. ‘Through the years, I’ve experienced first-hand the power of ASM International to connect materials science professionals and positively shape the industry,’ said Tirpak.’To now serve as president of the board is an honor and a privilege and one I’m looking forward to in the coming year.’ Tirpak, who currently serves on the ASM finance and investment committees, has also chaired ASM’s new products and services committee and the federal affairs committee. He is a senior program manager for the SCRA Applied R&D Advanced Materials Division and is also the executive director of the Forging Industry Association Department of Defense Manufacturing Consortium and program manager of the Defense Logistics Agency’s PRO-FAST Program. Additional new appointees to the board include: Dr. William E Frazier, vice president-elect. Dr Frazier served as a trustee from 2003 through 2007 and held positions on numerous ASM committees and currently is an associate editor for the Journal of Materials Engineering and Performance. Craig D Clauser, treasurer-elect. Clauser has served as Chairman of the ASM Chapter Operations Committee and the Handbook Committee and is founder, president and owner of Craig Clauser Engineering Consulting Inc, a company providing national metallurgical engineering services. Dr Ellen K Cerreta, trustee-elect. Dr Cerreta is the Group Leader for MST-8, the Materials in Radiation and Dynamic Extremes Group, at Los Alamos National Laboratory. In addition to serving on the ASM Board of Trustees, Dr. Cerreta is an adjunct faculty member attThe Institute of Shock Physics at Washington State University. Dr Ryan M Deacon, trustee-elect. Dr Deacon is a materials scientist in the materials engineering and research group of the DuPont Corporation and also serves as the corporate failure analyst for the company. Prof Sudipta Seal, trustee-elect. Prof Seal is the director of the Advanced Materials Processing and Analysis Center and NanoScience Technology Center at the University of Central Florida. This story is reprinted from material from ASM, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.

Schanen B.C.,Sanofi S.A. | Das S.,Advanced Materials Processing and Analysis Center | Reilly C.M.,Virginia Polytechnic Institute and State University | Warren W.L.,Sanofi S.A. | And 2 more authors.
PLoS ONE | Year: 2013

Immunomodulation by nanoparticles, especially as related to the biochemical properties of these unique materials, has scarcely been explored. In an in vitro model of human immunity, we demonstrate two catalytic nanoparticles, TiO2 (oxidant) and CeO2 (antioxidant), have nearly opposite effects on human dendritic cells and T helper (TH) cells. For example, whereas TiO2 nanoparticles potentiated DC maturation that led towards TH1-biased responses, treatment with antioxidant CeO2 nanoparticles induced APCs to secrete the anti-inflammatory cytokine, IL-10, and induce a TH2-dominated T cell profile. In subsequent studies, we demonstrate these results are likely explained by the disparate capacities of the nanoparticles to modulate ROS, since TiO2, but not CeO2 NPs, induced inflammatory responses through an ROS/inflammasome/IL-1β pathway. This novel capacity of metallic NPs to regulate innate and adaptive immunity in profoundly different directions via their ability to modulate dendritic cell function has strong implications for human health since unintentional exposure to these materials is common in modern societies. © 2013 Schanen et al.

Clukay C.J.,University of Central Florida | Grabill C.N.,University of Central Florida | Hettinger M.A.,University of Central Florida | Dutta A.,University of Central Florida | And 7 more authors.
Applied Surface Science | Year: 2014

This work shows that in situ reduction of metal ions bound at a polymer surface can form nanoparticles within the polymer matrix as well as at the interface, and the size and distribution of nanoparticles between the interface and subsurface depends upon the choice of reagents and reaction conditions. Tetrachloroaurate ions were bound to cross-linked SU-8 films that were functionalized using a variety of multi-functional amines, then reduced using one of several reagents. Reduction using sodium borohydride or sodium citrate generates bands of interspersed gold nanoparticles as much as 40 nm deep within the polymer, indicating that both the Au ions and the reducing agent can penetrate the surface enabling formation of nanoparticles within the polymer matrix. Nanoparticle formation can be confined nearer to the polymer interface by reducing with hydroquinone, or by processing the polymer film in aqueous media using high molecular-weight multifunctional amines that confine the gold ions at the interface. © 2013 Elsevier B.V.

Spano J.L.,Florida Institute of Technology | Schmitt T.J.,Florida Institute of Technology | Bailey R.C.,Florida Institute of Technology | Hannon T.S.,Florida Institute of Technology | And 6 more authors.
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2016

Melanoma is an underserved area of cancer research, with little focus on studying the effects of tumor extracellular matrix (ECM) properties on melanoma tumor progression, metastasis, and treatment efficacy. We've developed a Raman spectral mapping-based in-vitro screening platform that allows for nondestructive in-situ, multi-time point assessment of a novel potential nanotherapeutic adjuvant, nanoceria (cerium oxide nanoparticles), for treating melanoma. We've focused primarily on understanding melanoma tumor ECM composition and how it influences cell morphology and ICC markers. Furthermore, we aim to correlate this with studies on nanotherapeutic efficacy to coincide with the goal of predicting and preventing metastasis based on ECM composition. We've compiled a Raman spectral database for substrates containing varying compositions of fibronectin, elastin, laminin, and collagens type I and IV. Furthermore, we've developed a machine learning-based semi-quantitative analysis platform utilizing dimensionality reduction with subsequent pixel classification and semi-quantitation of ECM composition using Direct Classical Least Squares for classification and estimation of the reorganization of these components by taking 2D maps using Raman spectroscopy. Gaining an understanding of how tissue properties influence ECM organization has laid the foundation for future work utilizing Raman spectroscopy to assess therapeutic efficacy and matrix reorganization imparted by nanoceria. Specifically, this will allow us to better understand the role of HIF1a in matrix reorganization of the tumor microenvironment. By studying the relationship between substrate modulus and nanoceria's ability to inhibit an ECM that is conducive to tumor formation, we endeavor to show that nanoceria may prevent or even revert tumor conducive microenvironments. © 2016 SPIE.

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