Mechano-Optical Resonant Emission by Edge Angle Modulation of Wrinkled Graphene on Plasmonic Metal Gratings

Author(s):  
Ken Araki ◽  
Richard Z. Zhang
AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1780-1782
Author(s):  
G. Ben-Dor ◽  
T. Elperin ◽  
H. Li ◽  
E. Vasiliev ◽  
A. Chpoun ◽  
...  
Keyword(s):  

Author(s):  
Mikhail Dzyubenko ◽  
Sergey Masalov ◽  
Yuriy Kamenev ◽  
Ivan Kolenov ◽  
Viktor Pelipenko ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prashanth Gopalan ◽  
Yunshan Wang ◽  
Berardi Sensale-Rodriguez

AbstractWhile terahertz spectroscopy can provide valuable information regarding the charge transport properties in semiconductors, its application for the characterization of low-conductive two-dimensional layers, i.e., σs <  < 1 mS, remains elusive. This is primarily due to the low sensitivity of direct transmission measurements to such small sheet conductivity levels. In this work, we discuss harnessing the extraordinary optical transmission through gratings consisting of metallic stripes to characterize such low-conductive two-dimensional layers. We analyze the geometric tradeoffs in these structures and provide physical insights, ultimately leading to general design guidelines for experiments enabling non-contact, non-destructive, highly sensitive characterization of such layers.


Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 598
Author(s):  
Lin Wang ◽  
Ronghua Shi ◽  
Jian Dong

The dragonfly algorithm (DA) is a new intelligent algorithm based on the theory of dragonfly foraging and evading predators. DA exhibits excellent performance in solving multimodal continuous functions and engineering problems. To make this algorithm work in the binary space, this paper introduces an angle modulation mechanism on DA (called AMDA) to generate bit strings, that is, to give alternative solutions to binary problems, and uses DA to optimize the coefficients of the trigonometric function. Further, to improve the algorithm stability and convergence speed, an improved AMDA, called IAMDA, is proposed by adding one more coefficient to adjust the vertical displacement of the cosine part of the original generating function. To test the performance of IAMDA and AMDA, 12 zero-one knapsack problems are considered along with 13 classic benchmark functions. Experimental results prove that IAMDA has a superior convergence speed and solution quality as compared to other algorithms.


2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0021
Author(s):  
Clarabelle DeVries ◽  
Jeffrey J Nepple ◽  
Lucas Fowler ◽  
Sean Akers ◽  
Gail Pashos ◽  
...  

Introduction: Periacetabular osteotomy (PAO) has become a favored treatment for symptomatic acetabular dysplasia worldwide. Nevertheless, the parameters for optimal correction to avoid residual instability or iatrogenic impingement have not been defined. Purpose: The purposes of this study were (1) to assess the ability of PAO to correct femoral head coverage to normal ranges as measured by 3D CT scan and (2) to determine if postoperative radiographic parameters of dysplasia are accurate markers of optimal acetabular correction. Methods: A total of 43 hips (in 38 patients, mean 27.7 years, 88.4% female) were enrolled in this prospective cohort study at minimum 1 year after PAO. Postoperative femoral head coverage was assessed via low-dose CT and compared to normative data of asymptomatic hips from the literature. Anterior (3:00-1:15), lateral (1:00-11:00), and posterior (11:25-9:00) sector coverage was defined by averaging the coverage at 15 minute increments in each zone. Postoperative radiographs were utilized to measure lateral center edge angle (LCEA), anterior wall index (AWI), posterior wall index (PWI), and anterior center edge angle (ACEA). Good correction for each sector was defined as coverage from 1 SD below mean to 2 SD above mean. Results: Postoperatively, the anterior sector was normalized in 84% of hips, lateral sector in 84% of hips, and posterior sector in 86% of hips. Sixty-seven percent of hips were corrected to normative range in all three sectors and 19% were corrected in two sectors (86% in at least two sectors). LCEA and PWI showed the highest correlation with lateral and posterior sector coverage with Pearson’s correlation coefficients of 0.67 and 0.71 (p < 0.001), respectively. Weaker correlations were found between anterior coverage and the AWI and ACEA coverage (-0.16 and 0.15, respectively). Good correction was best correlated with the following target values for acetabular correction: LCEA 28°, AI 1°, AWI 0.37, ACEA 32°, and PWI 1.0. Conclusion: PAO can effectively normalize femoral head coverage compared to normative data. Good correction of each sector coverage ranged from 84-86% of cases. The proposed set of radiographic parameter targets were found to be reliable markers of femoral head coverage.


1985 ◽  
Vol 14 (2) ◽  
pp. 90-94 ◽  
Author(s):  
Peter E. Siegel

Author(s):  
P A Eynon ◽  
A Whitfield

The design of low-solidity diffuser vanes and the effect on the performance of a turbo-charger compressor is discussed. The effect of vane number and turning angle was investigated while maintaining a basic design with a solidity of 0.69 and a leading edge angle of 75°. This large leading edge angle was specifically chosen so that the vane would be aligned with the low flowrates close to surge. Tests were initially conducted with six, eight and ten vanes and a turning angle of 10°. Based on these results the ten-vane design was selected for further investigation with 15 and 20° of vane turning; this led to vane exit angles of 60 and 55° respectively. All results are compared with those obtained with the standard vaneless diffuser configuration and it was shown that all designs increased and shifted the peak pressure ratio to reduced flowrates. The peak efficiency was reduced relative to that obtained with the vaneless diffuser. Despite the low-solidity configuration none of the vane designs provided a broad operating range without the use of a variable geometry configuration. This was attributed to the selection of a large leading edge vane angle.


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