Improving effective bandwidth through compiler enhancement of global cache reuse

2002 ◽  
Author(s):  
C. Ding ◽  
K. Kennedy
Keyword(s):  
Effective Bandwidth ◽  
Cache Reuse

Enhanced frequency synchronization for concurrent aeroelastic and base vibratory energy harvesting using a softening nonlinear galloping energy harvester

2021 ◽  
pp. 1045389X2110263
Author(s):  
Shun Chen ◽  
David Eager ◽  
Liya Zhao
Keyword(s):  
Energy Harvesting ◽  
Electromechanical Coupling ◽  
Energy Harvester ◽  
Poor Performance ◽  
Effective Bandwidth ◽  
Frequency Synchronization ◽  
Periodic Oscillations ◽  
Energy Harvesters ◽  
Paper Form ◽  
Excited Oscillation

This paper proposes a softening nonlinear aeroelastic galloping energy harvester for enhanced energy harvesting from concurrent wind flow and base vibration. Traditional linear aeroelastic energy harvesters have poor performance with quasi-periodic oscillations when the base vibration frequency deviates from the aeroelastic frequency. The softening nonlinearity in the proposed harvester alters the self-excited galloping frequency and simultaneously extends the large-amplitude base-excited oscillation to a wider frequency range, achieving frequency synchronization over a remarkably broadened bandwidth with periodic oscillations for efficient energy conversion from dual sources. A fully coupled aero-electro-mechanical model is built and validated with measurements on a devised prototype. At a wind speed of 5.5 m/s and base acceleration of 0.1 g, the proposed harvester improves the performance by widening the effective bandwidth by 300% compared to the linear counterpart without sacrificing the voltage level. The influences of nonlinearity configuration, excitation magnitude, and electromechanical coupling strength on the mechanical and electrical behavior are examined. The results of this paper form a baseline for future efficiency enhancement of energy harvesting from concurrent wind and base vibration utilizing monostable stiffness nonlinearities.

scholarly journals Structural Engineering of Hierarchical Aerogels Comprised of Multi-dimensional Gradient Carbon Nanoarchitectures for Highly Efficient Microwave Absorption

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yongpeng Zhao ◽  
Xueqing Zuo ◽  
Yuan Guo ◽  
Hui Huang ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Structural Engineering ◽  
Carbon Nanomaterials ◽  
Wave Attenuation ◽  
Impedance Matching ◽  
Chemical Vapor ◽  
Electromagnetic Properties ◽  
Effective Bandwidth ◽  
Carbon Aerogels ◽  
Chemical Vapor Deposition Method

AbstractRecently, multilevel structural carbon aerogels are deemed as attractive candidates for microwave absorbing materials. Nevertheless, excessive stack and agglomeration for low-dimension carbon nanomaterials inducing impedance mismatch are significant challenges. Herein, the delicate “3D helix–2D sheet–1D fiber–0D dot” hierarchical aerogels have been successfully synthesized, for the first time, by sequential processes of hydrothermal self-assembly and in-situ chemical vapor deposition method. Particularly, the graphene sheets are uniformly intercalated by 3D helical carbon nanocoils, which give a feasible solution to the mentioned problem and endows the as-obtained aerogel with abundant porous structures and better dielectric properties. Moreover, by adjusting the content of 0D core–shell structured particles and the parameters for growth of the 1D carbon nanofibers, tunable electromagnetic properties and excellent impedance matching are achieved, which plays a vital role in the microwave absorption performance. As expected, the optimized aerogels harvest excellent performance, including broad effective bandwidth and strong reflection loss at low filling ratio and thin thickness. This work gives valuable guidance and inspiration for the design of hierarchical materials comprised of dimensional gradient structures, which holds great application potential for electromagnetic wave attenuation. "Image missing"

Electromagnetic Wave Absorbing and Mechanical Properties of Cement-Based Composite Panel with Different Nanomaterials

2017 ◽  
Vol 26 (1) ◽  
pp. 096369351702600
Author(s):  
Sun Yafei ◽  
Gao Peiwei ◽  
Peng Hailong ◽  
Liu Hongwei ◽  
Lu Xiaolin ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Electromagnetic Wave ◽  
Double Layer ◽  
Mechanical Performance ◽  
Interface Structure ◽  
Composite Panel ◽  
Effective Bandwidth ◽  
Composite Panels ◽  
Frequency Range ◽  
Triple Layer

This paper presents the microstructures and mechanical and absorbing properties of double and triple layer, cement-based, composite panels. The results obtained show that the frequency range in 2-18GHz had less than −10dB effective bandwidth, which correlates with 3.7and 10.8GHz in double and triple layer cement-based composite panels. Furthermore, the double layer panel's compressive strength at 7 and 28 days was 40.2 and 61.2MPa, respectively. For the triple layer panel, the strength values were 35.6MPa and 49.2MPa. The triple layer panel's electromagnetic wave (EMW) absorbing properties were superior compared to the properties of the double layer panel. However, the triple layer panel's mechanical performance was inferior to that of the double layer panel. This study proposes that carbon nanotubes can effectively improve the compressive strength and interface structure of cement-based composite panels.

No-reference method for image effective bandwidth estimation

2008 ◽  
Author(s):  
Barak Fishbain ◽  
Leonid Yaroslavsky ◽  
Ianir Ideses ◽  
Frédérique Roffet-Crété
Keyword(s):  
Reference Method ◽  
Effective Bandwidth ◽  
Bandwidth Estimation

scholarly journals Controllable permittivity in 3D Fe3O4/CNTs network for remarkable microwave absorption performances

RSC Advances ◽  
2017 ◽  
Vol 7 (43) ◽  
pp. 26801-26808 ◽  
Author(s):  
Lingyu Zhu ◽  
Xiaojun Zeng ◽  
Meng Chen ◽  
Ronghai Yu
Keyword(s):  
Carbon Nanotubes ◽  
Microwave Absorption ◽  
Effective Bandwidth ◽  
Three Dimension ◽  
Porous Spheres

Fe3O4 porous spheres are anchored onto carbon nanotubes (CNTs) to form three-dimension Fe3O4/CNTs nanocomposites, which exhibit remarkable EM microwave absorption performances with RL value of −51 dB at 5.52 GHz and effective bandwidth of 3.9 GHz.

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