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Your search keyword '"R. Raja Gopal"' showing total 3 results
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3 results on '"R. Raja Gopal"'

2. Performance of analysis crab leg based RF MEMS switch for defense and aerospace applications

Author

S. Sai Pravallika, G.V. Sai Prasanna, N. Siddaiah, G. R. K. Prasad, and R. Raja Gopal

Subjects
010302 applied physics, Microelectromechanical systems, Environmental Engineering, Materials science, business.industry, General Chemical Engineering, General Engineering, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Automotive engineering, Hardware and Architecture, 0103 physical sciences, Computer Science (miscellaneous), 0210 nano-technology, Aerospace, business, Biotechnology
Abstract

In this paper the design and modeling of capacitive shunt switch for k-ka band applications is presented. The proposed model for this design is the crab leg flexure. In order to reduce the squeeze film air damping, the perforated switch with reduced spring constant is designed. Analysis of designed switch has been carried out on the various parameters of the switch such as damping factor, switching time, quality factor and Eigen frequencies in order to design a reliable switch. The results indicate that the obtained pull in voltage is 3.1V for the dielectric gap of 1mm and spring constant of 2.95N/m2. Switching time is observed as 1.2ms and 2.15ms for the gap of 1mm and 1.5mm respectively. The capacitance ratio i.e. Cdown/Cup is 211.11 for HfO2 and 100.741 for Si3N4. Resonant frequency is obtained as 14.45 KHz. Return loss is calculated as-44.85dB at a frequency of 1GHz and -25.68dB at a frequency of 27.5GHz and insertion loss is obtained as -0.0447db at 1GHz and -1.0379dB at 27.5GHz. The maximum peak isolation is observed as -59.5dB at 1GHz frequency and -71dB at 27.5GHz frequency.

3. Bare plasmonic metal nanoparticles: synthesis, characterisation and in vitro toxicity assessment on a liver carcinoma cell line.

Author

Das N, Kumar A, Kumar Roy S, Kumar Satija N, and Raja Gopal R

Subjects
Cell Line, Tumor, Gold, Humans, Liver, Liver Neoplasms, Platinum toxicity, Silver toxicity, Metal Nanoparticles toxicity
Abstract

Metal nanoparticles have generated great interest due to their excellent optical and chemical properties. The widely used chemical method for synthesising nanoparticles involves capping agents for colloidal stability. However, there are scarce reports on the application of metal nanoparticles synthesised without using capping agents. Hence, there is a need to develop pristine nanoparticles devoid of capping that can be used for translational research. Here, the authors developed a facile and rapid method for synthesising bare metal nanoparticles (platinum/silver/gold) that are chemically reactive and stable for a month upon storage. They synthesised bare metal nanoparticles of sub-15 nm and characterised using standard techniques (UV-VIS-NIR/DLS/zeta//TEM/XRD). They assessed the safety of the synthesised nanoparticles on the liver carcinoma cell line (HepG2). Bare gold and platinum nanoparticles were non-toxic in comparison to bare silver nanoparticles. Bare metal nanoparticles were also checked for metal detection wherein antimony, mercury and chromium were detected using bare gold and silver nanoparticles. The spectroscopic shifts of the nanoparticles when bound to metals resulted in blue and red shifting of the plasmon band, indicating the sensing of metals. These results show that bare metal nanoparticles have the potential to emerge as a promising candidate for biomedical and sensing applications.

Published
2020
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