China
Africa
Explore chapters and articles related to this topic
Pyroelectric Nanogenerators in Energy Technology
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Tariq Altalhi, Nanogenerators, 2023
Ampattu R. Jayakrishnan, José P. B. da Silva, Sugumaran Sathish, Koppole Kamakshi, Koppole C. Sekhar
It is essential to monitor the reactors and the catalyst properties in order to measure the reactor condition and for enhancing the chemical processes [67, 68]. Reaction monitoring provides the direct information about the catalyst site properties via a change in temperature, composition, and or pressure. Thus, a PENG-based self-powered wireless nanosensor network (WNSN) plays an important role in direct detection of the surface reactions on the catalyst [67, 68]. Zarepour et al. [69] proposed a remote detector based on a PENG fitted with graphene-based nano-antennas [69]. The graphene antenna enables radiation in the range (0.1–10 THz). Figure 9.16 shows a schematic illustration of the WNSN-based reaction monitoring architecture. In order to understand the working mechanism, the authors selected Fischer-Tropsch synthesis (FTS) as a case study. Here, an iron-based fixed-bed FTS reactor is used and the catalyst sites have a dimension of 0.3 μm×0.3 μm with each site having a mass ˜1.5 fg. A rod made up of macro-scale wireless remote sinks is also deployed through the catalyst tube's axis. The internet is then connected to this wireless remote sink. FTS involves the process of converting natural gas to liquid hydrocarbons in a chemical reactor [69]. The different chemical reactions and the corresponding chemical species evolved are shown in Table 9.2.
Scattering of eigenmodes of planar dielectric waveguide with PEC wall by graphene strip grating at THz
Published in Waves in Random and Complex Media, 2021
Mstislav E. Kaliberda, Leonid M. Lytvynenko, Sergey A. Pogarsky
The simple way to control the conductivity of graphene by bias voltage and the possibility to support surface plasmons predetermine its use in THz antennas. However, the absorption significantly increases near the plasmon resonances. This fact can limit the radiation efficiency of graphene plasmon antennas. In [10–12], the radiation efficiency of the proposed graphene leaky-wave antenna (LWA) is limited to 20%. The radiation efficiency of the graphene LWA based on cylindrical waveguide reaches 50% in [13]. In [14], the radiation efficiency of the graphene LWA is about 80%. At the same time, the advantage of graphene antenna is the ability to dynamically tune its characteristics. LWAs with graphene strips placed on the grounded dielectric slab or inside it are studied in [12,14,15].
High-performance printable 2.4 GHz graphene-based antenna using water-transferring technology
Published in Science and Technology of Advanced Materials, 2019
Weijia Wang, Chao Ma, Xingtang Zhang, Jiajia Shen, Nobutaka Hanagata, Jiangtao Huangfu, Mingsheng Xu
We have demonstrated the fabrication of high-performance 2.4 GHz graphene-based antenna by printing and using water-transferrable paper. Such a low-temperature and environment-friendly process is suitable for scalable production of graphene-based antennas. Our small-sized graphene dipole antenna has −10 dB bandwidth of 2.297–2.510 GHz (8.9%) with a maximum gain of 0.7 dBi. The performance of our graphene antenna satisfies the application requirements of IoT sensing and suggests its feasibility of replacing conventional metallic antennas in those applications.