Zobrazeno 1 - 10
of 4 363
pro vyhledávání: '"VHF"'
Autor:
Shubham Bansal, Rajendra Singh Yadav
Publikováno v:
Journal of Engineering and Applied Science, Vol 71, Iss 1, Pp 1-18 (2024)
Abstract This article aims to examine an unsteady 2-D laminar flow of magnetohydrodynamic fluid caused by an elastic surface immersed in a permeable medium under the influence of thermal radiation and extended heat flux. Thermal conductivity and visc
Externí odkaz:
https://doaj.org/article/69370995fc8e436ba596c529823d8507
Publikováno v:
Физика волновых процессов и радиотехнические системы, Vol 27, Iss 2, Pp 100-110 (2024)
Background. Currently, there is an intensive development of radar systems for remote sensing of the Earth, including those placed on unmanned aerial vehicles. Synthetic aperture radars are an effective means of round-the-clock and all-weather observa
Externí odkaz:
https://doaj.org/article/74fc1783524e43b89931cb261ce861b3
Autor:
Christine Reusch, José Bernardo Vindas-Picado, Carolin Scholz, Uwe Hoffmeister, Christian C. Voigt
Publikováno v:
Global Ecology and Conservation, Vol 54, Iss , Pp e03112- (2024)
Light pollution is spreading around the world, causing a variety of problems, particularly for nocturnal animals such as bats. As urban areas expand, attic-dwelling bats face the problem of being exposed to more and more artificial light as they move
Externí odkaz:
https://doaj.org/article/0adf768c97ff446999a817eeded550ab
Autor:
Bo Chen, Yihao Xu, Chen Zhou, Yuqiang Zhang, Yi Liu, Tong Xu, Bin Xu, Jian Feng, Ting Lan, Haiyin Qing, Zhongxin Deng, Xiang Wang, Xinmiao Zhang
Publikováno v:
Frontiers in Astronomy and Space Sciences, Vol 11 (2024)
There is a long history of using VHF radar systems to detect ionospheric irregularities based on the theory of coherent scattering. According to previous work, there is a high occurrence of field-aligned irregularities (FAIs) in the ionospheric E-reg
Externí odkaz:
https://doaj.org/article/f0b7bc6b14f0429aaa542d78fafbc175
Autor:
Dongxia Liu, Fengquan Li, Xiushu Qie, Zhuling Sun, Yu Wang, Shanfeng Yuan, Chunfa Sun, Kexin Zhu, Lei Wei, Huimin Lyu, Rubin Jiang
Publikováno v:
Geophysical Research Letters, Vol 51, Iss 16, Pp n/a-n/a (2024)
Abstract The evolution of charge structure involved in lightning discharge of a thunderstorm over the central Tibetan Plateau is investigated for the first time, based on the data from very high frequency interferometer, radar and sounding. During th
Externí odkaz:
https://doaj.org/article/648b3d8f8ceb4ac4874219347ad01932
Publikováno v:
Maritime Transport Research, Vol 7, Iss , Pp 100114- (2024)
Maritime transport serves as a critical component of global trade and logistics, enabling the movement of goods and resources across oceans and waterways. Especially in busy waterways and ports, effective and accurate communication is essential, as i
Externí odkaz:
https://doaj.org/article/4e0d80e219374a7c95b520b384b15a73
Autor:
Gongwen Gan, Yaqin Yin, Yue Cheng, Jie Luo, Zongliang Zheng, Xi Zhang, Fei Xie, Ziming Li, Liwen Dian, Gaojie Zou, Feifei Qiu, Zhongyin Zhu, Guoqing Gou
Publikováno v:
Materials Today Advances, Vol 22, Iss , Pp 100505- (2024)
we deeply dived multi-phase-based 0.16BaFeO3-0.84MgFe2O4 ferrite for VHF antennas. The structural and magneto-dielectric properties synthesized at various temperatures (1100 °C, 1125 °C, 1150 °C and 1175 °C) were investigated. The results demonst
Externí odkaz:
https://doaj.org/article/be28baa2a36a475a9cd6fccfb73b5783
Autor:
Aryanti Karlina Nurendyastuti, Mohammad Bagus Adityawan, Muhammad Rizki Purnama, Mohammad Sigit Arifianto, Mohammad Farid, Arno Adi Kuntoro, Widyaningtias, Mochamad Mardi Marta Dinata, Arumjeni Mitayani
Publikováno v:
Journal of Applied Science and Engineering, Vol 27, Iss 4, Pp 2285-2294 (2024)
Indonesia, located in the zone of “Ring of Fire,” has a high tsunami risk, specifically from those induced by earthquakes. The 2004 Aceh Tsunami and the 2006 Pangandaran Tsunami demonstrated that tsunamis could cause major damage to coastal areas
Externí odkaz:
https://doaj.org/article/b8bc627c5c4c4e2ab6738cda335b0374
Publikováno v:
Iranian Journal of Electrical and Electronic Engineering, Vol 19, Iss 4, Pp 1-11 (2023)
In this article, an active electrically small Horn antenna for very high frequency (VHF) and ultra-high frequency (UHF) frequencies is presented. The proposed horn antenna has a height of 5 cm and a diameter of 4.28 cm which can cover 6-12 GHz withou
Externí odkaz:
https://doaj.org/article/b5830a9c34ca4993a6138b9df8c041bd
Autor:
Berngardt, O. I.1 berng@iszf.irk.ru, Lebedev, V. P.1, Kutelev, K. A.1, Kushnarev, D. S.1, Grkovich, K. V.1
Publikováno v:
Radiophysics & Quantum Electronics. Jan2018, Vol. 60 Issue 8, p618-639. 22p.