Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Adaptive filtering (1)
- Avalanches (1)
- Chemical anchors (1)
- Crystal plasticity (1)
- Defect chemistry (1)
-
- Dislocation avalanches (1)
- Dislocation correlations (1)
- Dislocation structure (1)
- Electrocatalysis (1)
- Face-centered cubic (1)
- Forest flight (1)
- Hardness (1)
- High entropy ceramics (1)
- Integrated electrodes (1)
- Lithium–sulfur batteries (1)
- Lithography (1)
- MARG sensor (1)
- Materials for optics (1)
- Materials science (1)
- Motion planning (1)
- Nano-array (1)
- Nanofabrication (1)
- Nanoindentation (1)
- Nanostructures (1)
- Noise (1)
- Perovskite (1)
- Plasmon (1)
- Plasticity (1)
- Polysulfides (1)
- Pop-in (1)
Articles 1 - 8 of 8
Full-Text Articles in Engineering
From Statistical Correlations To Stochasticity And Size Effects In Sub-Micron Crystal Plasticity, Hengxu Song, Stefanos Papanikolaou
From Statistical Correlations To Stochasticity And Size Effects In Sub-Micron Crystal Plasticity, Hengxu Song, Stefanos Papanikolaou
Faculty & Staff Scholarship
Metals in small volumes display a strong dependence on initial conditions, which translates into size effects and stochastic mechanical responses. In the context of crystal plasticity, this amounts to the role of pre-existing dislocation configurations that may emerge due to prior processing. Here, we study a minimal but realistic model of uniaxial compression of sub-micron finite volumes. We show how the statistical correlations of pre-existing dislocation configurations may influence the mechanical response in multi-slip crystal plasticity, in connection to the finite volume size and the initial dislocation density. In addition, spatial dislocation correlations display evidence that plasticity is strongly influenced …
Bending Nanoindentation And Plasticity Noise In Fcc Single And Polycrystals, Ryder Bolin, Hakan Yavas, Hengxu Song, Kevin J. Hemker, Stefanos Papanikolaou
Bending Nanoindentation And Plasticity Noise In Fcc Single And Polycrystals, Ryder Bolin, Hakan Yavas, Hengxu Song, Kevin J. Hemker, Stefanos Papanikolaou
Faculty & Staff Scholarship
Abstract: We present a high-throughput nanoindentation study of in situ bending effects on incipient plastic deformation behavior of polycrystalline and single-crystalline pure aluminum and pure copper at ultranano depths (< 200 nm). We find that hardness displays a statistically inverse dependence on in-plane stress for indentation depths smaller than 10 nm, and the dependence disappears for larger indentation depths. In contrast, plastic noise in the nanoindentation force and displacement displays statistically robust noise features, independently of applied stresses. Our experimental results suggest the existence of a regime in Face Centered Cubic (FCC) crystals where ultranano hardness is sensitive to residual applied stresses, but plasticity pop-in noise is insensitive to it.
A Review Of 2d And 3d Plasmonic Nanostructure Array Patterns: Fabrication, Light Management And Sensing Applications, Sujan Kassani, Katherine Curtin, Nianqiang Wu
A Review Of 2d And 3d Plasmonic Nanostructure Array Patterns: Fabrication, Light Management And Sensing Applications, Sujan Kassani, Katherine Curtin, Nianqiang Wu
Faculty & Staff Scholarship
Abstract: This review article discusses progress in surface plasmon resonance (SPR) of two-dimensional (2D) and three-dimensional (3D) chip-based nanostructure array patterns. Recent advancements in fabrication techniques for nano-arrays have endowed researchers with tools to explore a material’s plasmonic optical properties. In this review, fabrication techniques including electron-beam lithography, focused-ion lithography, dip-pen lithography, laser interference lithography, nanosphere lithography, nanoimprint lithography, and anodic aluminum oxide (AAO) template-based lithography are introduced and discussed. Nano-arrays have gained increased attention because of their optical property dependency (lightmatter interactions) on size, shape, and periodicity. In particular, nano-array architectures can be tailored to produce and tune plasmonic …
Exploration Of High Entropy Ceramics (Hecs) With Computational Thermodynamics - A Case Study With Lamno3±Δ, Yu Zhong, Hooman Sabarou, Xiaotian Yan, Mei Yang, Michael C. Gao, Xingbo Liu, Richard D. Sisson Jr.
Exploration Of High Entropy Ceramics (Hecs) With Computational Thermodynamics - A Case Study With Lamno3±Δ, Yu Zhong, Hooman Sabarou, Xiaotian Yan, Mei Yang, Michael C. Gao, Xingbo Liu, Richard D. Sisson Jr.
Faculty & Staff Scholarship
The concept of the new category materials high entropy ceramics (HECs) has been proposed several years ago, which is directly borrowed from high entropy alloys (HEAs). It quickly attracts a lot of interests and displays promising properties. However, there is no clear definition of HECs differentiating it from HEAs, as it is still in its early research stage. In the current work, we are trying to use the classic perovskite LaMnO3±δ (LMO) to demonstrate the fundamental differences between HECs and HEAs. We have adopted the integrated defect chemistry and CALPHAD approach to investigate the mixing behavior and how it is …
Quaternion-Based Robust Attitude Estimation Using An Adaptive Unscented Kalman Filter, Antonio C. B. Chiella, Bruno O. S. Teixeira, Guilherme A. S. Pereira
Quaternion-Based Robust Attitude Estimation Using An Adaptive Unscented Kalman Filter, Antonio C. B. Chiella, Bruno O. S. Teixeira, Guilherme A. S. Pereira
Faculty & Staff Scholarship
This paper presents the Quaternion-based Robust Adaptive Unscented Kalman Filter (QRAUKF) for attitude estimation. The proposed methodology modifies and extends the standard UKF equations to consistently accommodate the non-Euclidean algebra of unit quaternions and to add robustness to fast and slow variations in the measurement uncertainty. To deal with slow time-varying perturbations in the sensors, an adaptive strategy based on covariance matching that tunes the measurement covariance matrix online is used. Additionally, an outlier detector algorithm is adopted to identify abrupt changes in the UKF innovation, thus rejecting fast perturbations. Adaptation and outlier detection make the proposed algorithm robust to …
On The Unusual Amber Coloration Of Nanoporous Sol-Gel Processed Al-Doped Silica Glass: An Experimental Study, Alvin Chang, Yujuan He, Maria A. Torres Arango, Maoyu Wang, Yang Ren, Zhenxing Feng, Chih-Hung Chang, Knostantinos A. Sierros
On The Unusual Amber Coloration Of Nanoporous Sol-Gel Processed Al-Doped Silica Glass: An Experimental Study, Alvin Chang, Yujuan He, Maria A. Torres Arango, Maoyu Wang, Yang Ren, Zhenxing Feng, Chih-Hung Chang, Knostantinos A. Sierros
Faculty & Staff Scholarship
Silica is the most abundant component on the earth’s surface. It plays an important role in many natural processes. Silica is also a critical material for a wide range of technical applications such as in optics and electronics. In this work, we discuss our recent experimental observation of the unusual amber coloration of aluminum doped sol-gel glass that has not been reported in the past. We characterized Al-doped sol-gel glasses, prepared at different sintering temperature, using a plethora of techniques to investigate the origin of this unusual coloration and to understand their structural and chemical properties. We used these experimental …
Programmed Design Of A Lithium–Sulfur Battery Cathode By Integrating Functional Units, Zhipeng Zeng, Wei Li, Qiang Wang, Xingbo Liu
Programmed Design Of A Lithium–Sulfur Battery Cathode By Integrating Functional Units, Zhipeng Zeng, Wei Li, Qiang Wang, Xingbo Liu
Faculty & Staff Scholarship
Sulfur is considered to be one of the most promising cathode materials due to its high theoretical specific capacity and low cost. However, the insulating nature of sulfur and notorious “shuttle effect” of lithium polysulfides (LiPSs) lead to severe loss of active sulfur, poor redox kinetics, and rapid capacity fade. Herein, a hierarchical electrode design is proposed to address these issues synchronously, which integrates multiple building blocks with specialized functions into an ensemble to construct a self‐supported versatile cathode for lithium–sulfur batteries. Nickel foam acts as a robust conductive scaffold. The heteroatom‐doped host carbon with desired lithiophilicity and electronic conductivity …
Gnss/Lidar-Based Navigation Of An Aerial Robot In Sparse Forests, Antonio C. Chiella, Henrique N. Machado, Bruno O.S. Teixeira, Guilherme A.S. Pereira
Gnss/Lidar-Based Navigation Of An Aerial Robot In Sparse Forests, Antonio C. Chiella, Henrique N. Machado, Bruno O.S. Teixeira, Guilherme A.S. Pereira
Faculty & Staff Scholarship
Autonomous navigation of unmanned vehicles in forests is a challenging task. In such environments, due to the canopies of the trees, information from Global Navigation Satellite Systems (GNSS) can be degraded or even unavailable. Also, because of the large number of obstacles, a previous detailed map of the environment is not practical. In this paper, we solve the complete navigation problem of an aerial robot in a sparse forest, where there is enough space for the flight and the GNSS signals can be sporadically detected. For localization, we propose a state estimator that merges information from GNSS, Attitude and Heading …