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Displaying 976 - 1000 of 2122

Metal Additive Manufacturing Standardization in Support of Qualification and Certification

February 28, 2017
Author(s)
Mohsen Seifi, Michael Gorelik, Jess Waller, Nik Hrabe, Nima Shamsaei, Steve Daniewicz, John J. Lewandowski
As the metal Additive Manufacturing (AM) industry moves towards industrial production, the need for qualification standards covering all aspects of the technology becomes ever more prevalent. While some standards and specifications for documenting the

Dynamical Heterogeneity in a Vapor-Deposited Polymer Glass

February 23, 2017
Author(s)
Jack F. Douglas, Wengang Zhang, Francis W. Starr
Recently, there has been great interest in 'ultrastable' glasses formed via vapor deposition, both because of emerging applications of these materials (e.g., active layers in light-emitting diodes and photovoltaics) and, theoretically, as materials for

Entropy-Driven Segregation of Polymer-Grafted Nanoparticles under Confinement

February 22, 2017
Author(s)
Ren Zhang, Bongjoon Lee, Christopher Stafford, J. F. Douglas, Andrey V. Dobrynin, Michael R. Bockstaller, Alamgir Karim
Polymer-grafted nanoparticles (PGNPs) have attracted much attention due to the enhanced dispersion in polymeric materials via an interacting brush layer that enables unique functionality and stability. The miscibility and organization of nanoparticles

Predicting low-temperature free energy landscapes with flat-histogram Monte Carlo methods

February 21, 2017
Author(s)
Nathan Mahynski, Marco A. Blanco Medina, Jeffrey R. Errington, Vincent K. Shen
We present a method of predicting the free energy landscape of fluids at low temperatures from flat-histogram grand canonical Monte Carlo simulations performed at higher ones. We illustrate our approach for both pure and multicomponent systems using two

Duality of Dislocation Content of Grain Boundaries

February 19, 2017
Author(s)
John W. Cahn, Yuri Mishin, A Suzuki
The Frank-Bilby equation (FBE) can give many solutions for the dislocation content of a grain boundary (GB); most of them are considered to have little physical reality except in limited ranges of the angles which characterize low-angle GBs. We explore two

Impact of UV irradiation on multiwall carbon nanotubes in nanocomposites: formation of entangled surface layer and mechanisms of release resistance

January 31, 2017
Author(s)
Tinh Nguyen, Elijah J. Petersen, Bastien T. Pellegrin, Justin M. Gorham, Thomas F. Lam, Minhua Zhao, Li Piin Sung
Carbon nanotubes (CNTs) are increasingly used in consumer and structural polymeric products to enhance a variety of properties. Under weathering, the polymer matrix will degrade and the nanofillers will potentially be released from the products, which

Tuning flexibility to control selectivity in soft porous crystals

January 31, 2017
Author(s)
Nathan Mahynski, Vincent K. Shen
We use flat-histogram Monte Carlo simulations to study how changing the flexibility of soft porous crystals (SPCs) affects their selective adsorption of a binary, size-asymmetric supercritical fluid. Specifically, we consider mesoporous SPCs which have

Insights into Cruciform Sample Design

January 30, 2017
Author(s)
Adam A. Creuziger, Mark A. Iadicola, Timothy J. Foecke, Evan Rust, Dilip K. Banerjee
Four different cruciform sample designs, based on the work of Abu-Farha et al, were studied in this paper. The original design of Abu-Farha was validated at room temperature for a thicker sample, and two modified sample geometries that would permit thinner

Homogenization Kinetics of a Nickel-based Superalloy Produced by Powder Bed Fusion Laser Sintering

January 26, 2017
Author(s)
Fan Zhang, Lyle E. Levine, Andrew J. Allen, Eric Lass, Sudha Cheruvathur, Mark R. Stoudt, Maureen E. Williams, Yaakov S. Idell, Carelyn E. Campbell
Additively manufactured (AM) metal components often exhibit fine dendritic microstructures and elemental segregation due to the initial rapid solidification and subsequent melting and cooling during the build process, which without homogenization would

Temperature dependence of electron density and electron-electron interactions in monolayer epitaxial graphene grown on SiC

January 25, 2017
Author(s)
Chieh W. Liu, Chiashain Chuang, Yanfei Yang, Randolph Elmquist, Yi-Ju Ho, Hsin Y. Lee, Chi-Te Liang
We report carrier density measurements and electron-electron (e-e) interactions in monolayer epitaxial graphene grown on SiC. The temperature (T)-independent carrier density determined from the Shubnikov-de Haas (SdH) oscillations clearly demonstrates that

Magnetic Properties and Applications of Engineered Nanomaterials

January 20, 2017
Author(s)
Cindi L. Dennis
This chapter will review the fundamentals of nanomagnetism, including its origins, the different types, and their response at the nanoscale, followed by applications of nanomagnetics. Unfortunately, due to space constraints, this chapter cannot be

Structure and Order in Organic Semiconductors

January 17, 2017
Author(s)
Chad R. Snyder, Dean M. DeLongchamp, Ryan C. Nieuwendaal, Andrew A. Herzing
Several techniques for characterizing semiconducting polymer order on different length scales are presented, including (1) differential scanning calorimetry (DSC), (2) solid state nuclear magnetic resonance spectroscopy (NMR), (3) transmission electron

Sorting carbon nanotubes

January 12, 2017
Author(s)
Ming Zheng
Sorting of single-wall carbon nanotubes by their electronic and atomic structures in liquid phases is reviewed in this chapter. We first introduce the sorting problem, then provide an overview of several sorting methodologies, following roughly the

Benchmark Problems for Phase Field Modeling

January 2, 2017
Author(s)
Andrea Jokisaari, P W. Voorhees, Jonathan E. Guyer, James A. Warren, O. G. Heinonen
We present the first set of benchmark problems for phase field models that are being devel- oped by the Center for Heirarchical Materials Design (CHiMaD) and the National Institute of Standards and Technology (NIST). While many scientific research areas
Displaying 976 - 1000 of 2122