scholarly journals Flexible Gallium Nitride for High-Performance, Strainable Radio-Frequency Devices

2017 ◽  
Vol 29 (47) ◽  
pp. 1701838 ◽  
Author(s):  
Nicholas R. Glavin ◽  
Kelson D. Chabak ◽  
Eric R. Heller ◽  
Elizabeth A. Moore ◽  
Timothy A. Prusnick ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Radio Frequency ◽  
High Performance

scholarly journals Flexible Gallium Nitride: Flexible Gallium Nitride for High-Performance, Strainable Radio-Frequency Devices (Adv. Mater. 47/2017)

2017 ◽  
Vol 29 (47) ◽  
pp. 1770338 ◽  
Author(s):  
Nicholas R. Glavin ◽  
Kelson D. Chabak ◽  
Eric R. Heller ◽  
Elizabeth A. Moore ◽  
Timothy A. Prusnick ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Radio Frequency ◽  
High Performance

Sitsen: Passive sitting posture sensing based on wireless devices

2021 ◽  
Vol 17 (7) ◽  
pp. 155014772110248
Author(s):  
Miaoyu Li ◽  
Zhuohan Jiang ◽  
Yutong Liu ◽  
Shuheng Chen ◽  
Marcin Wozniak ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Radio Frequency Identification ◽  
High Performance ◽  
Learning Algorithm ◽  
Low Cost ◽  
Recognition System ◽  
Sitting Posture ◽  
Average Accuracy ◽  
Phase Variations ◽  
Window Approach

Physical health diseases caused by wrong sitting postures are becoming increasingly serious and widespread, especially for sedentary students and workers. Existing video-based approaches and sensor-based approaches can achieve high accuracy, while they have limitations like breaching privacy and relying on specific sensor devices. In this work, we propose Sitsen, a non-contact wireless-based sitting posture recognition system, just using radio frequency signals alone, which neither compromises the privacy nor requires using various specific sensors. We demonstrate that Sitsen can successfully recognize five habitual sitting postures with just one lightweight and low-cost radio frequency identification tag. The intuition is that different postures induce different phase variations. Due to the received phase readings are corrupted by the environmental noise and hardware imperfection, we employ series of signal processing schemes to obtain clean phase readings. Using the sliding window approach to extract effective features of the measured phase sequences and employing an appropriate machine learning algorithm, Sitsen can achieve robust and high performance. Extensive experiments are conducted in an office with 10 volunteers. The result shows that our system can recognize different sitting postures with an average accuracy of 97.02%.

scholarly journals Gallium nitride catalyzed the direct hydrogenation of carbon dioxide to dimethyl ether as primary product

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chang Liu ◽  
Jincan Kang ◽  
Zheng-Qing Huang ◽  
Yong-Hong Song ◽  
Yong-Shan Xiao ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Dimethyl Ether ◽  
High Performance ◽  
Density Functional ◽  
Value Added ◽  
Density Functional Theory Calculations ◽  
Product Distribution ◽  
Spectroscopic Studies ◽  
Direct Hydrogenation ◽  
Hydrogenation Of Co

AbstractThe selective hydrogenation of CO2 to value-added chemicals is attractive but still challenged by the high-performance catalyst. In this work, we report that gallium nitride (GaN) catalyzes the direct hydrogenation of CO2 to dimethyl ether (DME) with a CO-free selectivity of about 80%. The activity of GaN for the hydrogenation of CO2 is much higher than that for the hydrogenation of CO although the product distribution is very similar. The steady-state and transient experimental results, spectroscopic studies, and density functional theory calculations rigorously reveal that DME is produced as the primary product via the methyl and formate intermediates, which are formed over different planes of GaN with similar activation energies. This essentially differs from the traditional DME synthesis via the methanol intermediate over a hybrid catalyst. The present work offers a different catalyst capable of the direct hydrogenation of CO2 to DME and thus enriches the chemistry for CO2 transformations.

High performance, self-powered and thermally stable 200–750 nm spectral responsive gallium nitride (GaN) based broadband photodetectors

2021 ◽  
Vol 225 ◽  
pp. 111033
Author(s):  
Nanda Kumar Reddy Nallabala ◽  
Srinivas Godavarthi ◽  
Venkata Krishnaiah Kummara ◽  
Mohan Kumar Kesarla ◽  
C. Yuvaraj ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
High Performance ◽  
Thermally Stable ◽  
Self Powered

scholarly journals High performance metal–insulator–graphene diodes for radio frequency power detection application

Nanoscale ◽  
2017 ◽  
Vol 9 (33) ◽  
pp. 11944-11950 ◽  
Author(s):  
Mehrdad Shaygan ◽  
Zhenxing Wang ◽  
Mohamed Saeed Elsayed ◽  
Martin Otto ◽  
Giuseppe Iannaccone ◽  
...  
Keyword(s):  
Radio Frequency ◽  
High Performance ◽  
Radio Frequency Power ◽  
Metal Insulator ◽  
Frequency Power

Metal–insulator–graphene diodes are proved to be able to deliver high performance, and meanwhile are suitable for radiofrequency power detection.

Reliability evaluation of wearable radio frequency identification tags: Design and fabrication of a two-part textile antenna

2018 ◽  
Vol 89 (4) ◽  
pp. 560-571 ◽  
Author(s):  
Xiaochen Chen ◽  
Leena Ukkonen ◽  
Johanna Virkki
Keyword(s):  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Integrated Circuit ◽  
High Performance ◽  
Cyclic Strain ◽  
Moist Environment ◽  
Frequency Identification ◽  
Identification Tags ◽  
Cost Efficient ◽  
The One

Passive radio frequency identification-based technology is a convincing approach to the achievement of versatile energy- and cost-efficient wireless platforms for future wearable applications. By using two-part antenna structures, the antenna-electronics interconnections can remain non-stressed, which can significantly improve the reliability of the textile-embedded wireless components. In this article, we describe fabrication of two-part stretchable and non-stretchable passive ultra-high frequency radio frequency identification textile tags using electro-textile and embroidered antennas, and test their reliability when immersed as well as under cyclic strain. The results are compared to tags with traditional one-part dipole antennas fabricated from electro-textiles and by embroidery. Based on the results achieved, the initial read ranges of the two-part antenna tags, around 5 m, were only slightly shorter than those of the one-part antenna tags. In addition, the tag with two-part antennas can maintain high performance in a moist environment and during continuous stretching, unlike the one-part antenna tag where the antenna-integrated circuit attachment is under stress.

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