Sampled Reference Frame Algorithm Based on Space Vector Pulse Width Modulation for Five Level Cascaded H-Bridge Inverter

In This paper the Sampled Reference Frame Algorithm for Five Level Cascaded H-Bridge Inverter is presented. This simple method is less computation method than Sector Identification. This SVPWM can drive any Multilevel Inverter with good DC utilization, less switching stress. This is used for high voltage and high power applications. By using Sampled Reference Frame Algorithm, there is no use of look up tables, sector selection, no need of reference voltage and angle information, 3φ to 2φ transformation. The inverter's structure of these inverters is developed by using MATLAB SIMULINK software

Nickel nano-wires filled alumina templates for microwave electronics

The magnetic properties of arrays of one-dimensional nickel nano-wires with high aspect ratio have been studied by a Network Analyzer based ferromagnetic resonance (NA-FMR) technique using a flip-chip method in frequency domain. The frequency-field data [fr(Ho)] is observed to be tunable up to 14-16 GHz with an applied field (Ho) ]of 4 kOe. The fundamental magnetic parameters such as the spontaneous magnetization, gyromagnetic ratio (γ), and magnetic anisotropies of the nanowires were derived from f r(HO) data. The resonance response of the Ni nanowire is explained theoretically by calculating the transmission parameter using a simple method; where the nanowire in the alumina matrix is represented by an effective medium. The power transmitted per unit area in the coplanar waveguide transmission line with the sample is calculated from the Poynting vector using the RF field components at all positions around the signal line in the waveguide. © 2009 IEEE

Size dependent microwave properties of ferrite nanoparticles: Application to microwave devices

We studied the magnetic field dependence of the resonance frequency (fr) and frequency linewidth (Δf) of iron oxide nanoparticles (Fe3 O4) with different particle sizes spin-coated on a coplanar waveguide. Using a vector network analyzer, we find that the resonance frequency increases with an increase in applied field for all particle sizes, while Δf decreases with the increase in the particle size. We have also carried out a theoretical study using the power absorbed by the different regions of the coplanar waveguide and found that the results are in accordance with the experiment. © 2009 American Institute of Physics

Microstrip-tunable band-pass filter using ferrite (Nanoparticles) coupled lines

In this paper, we designed, fabricated, and characterized a novel band-pass filter using ferrite nanoparticles as the active element in microstrip geometry. Two 50-ω Cu transmitting/receiving antennas (one side fed and the other side shorted) were fabricated by photolithography on top of a thick layer of ferrites (Fe3O4) nanoparticles. The filter is based on ferromagnetic resonance. It is very compact and has very wide frequency tunability. Linear dependence is obtained between the resonance frequency and the applied dc magnetic field. The bandwidth and Q-factor of the filter are observed to be almost constant over the field range studied. Theoretical calculations have been performed considering the ferrite nanoparticles as an effective medium with effective demagnetization. The frequency for different applied fields was calculated for different volume fractions, and it is shown theoretically that the control of band-pass frequency can also be achieved by varying the volume fraction of the nanoparticles in the effective medium. © 2009 IEEE

High frequency study of core-shell and uncoated Fe 3O 4 nanoparticles

Nanoparticles of Fe 3O 4 (core) were synthesized and some were covered with a thin layer of Au (shell) to create a core-shell structure. The dynamic magnetic properties were studied using a vector network analyzer. It was found that, at a given applied magnetic field, the core-shell nanoparticles resonate at lower frequency compared to the uncoated Fe 3O 4 nanoparticles and the resonance frequency increased with increasing applied field for both the core-shell and the uncoated nanoparticles. Also, the core-shell nanoparticles exhibited additional resonances. Further, the core-shell nanoparticles exhibited a larger linewidth compared to the uncoated counterparts for all the particle sizes. The experimental absorption data have been compared with the results obtained from an effective medium theory. © 2012 American Institute of Physics

Biomedical Waste Management in Prosthodontic Dentistry

Biomedical waste (BMW) is a global issue today. Common producers of biomedical waste include hospitals, health clinics, nursing homes, medical research laboratories, offices of physicians, dentists, and veterinarians, home health care, and funeral homes. It must be properly managed to protect the general public, specifically healthcare and sanitation workers who are regularly exposed to biomedical waste as an occupational hazard. The materials used in prosthodontic dentistry are large in numbers. They are Impression Materials, Gypsum Products, Cements. And it was segregation according to colour code. If we want to protect our environment and health of community we must sensitize ourselves to this important issue not only in the interest of health managers but also in the interest of community

High frequency study of core-shell reusable CoFe2O 4-ZnO nanospheres

Recently, coated nanoshells combined with magnetic nanoparticles and cancer-cell-specific antibodies have been used to develop a multifunctional platform for simultaneously diagnosing and treating cancer, via magnetic resonance imaging and photothermal therapy. For this application, core-shell nano-spheres with a low resonance frequency (low GHz range) in a strong applied field are required. In this aspect, ferromagnetic resonance experiment is an important tool for determining the dynamic properties of nano-materials. Magnetic field dependence of resonance frequency (fr) and linewidths (Δ and ΔH) for both the ZnO coated and uncoated CoFe 2O4 hollow spheres are studied using a vector network analyzer. As compared to uncoated CoFe2O4 hollow sphere, ZnO coated CoFe2O4 showed reduced resonance frequency, larger Δ and ΔH, reduced gyromagnetic ratio and effective fields. The experimental results are confirmed with the effective medium theory. © 2014 AIP Publishing LLC