applied frequency
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Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Lingtao Zhang ◽  
Fan Liu ◽  
Ting Wang ◽  
Shilin Wu ◽  
Yamei Jin ◽  
...  

As an emerging electrotechnology, induced electric field has attracted extensive attention in the development of innovative heat treatment equipment. In this study, a resistance heating unit based on induced electric field was built for inner heating of aqueous electrolyte solutions as well as liquid foods, such as vinegar. NaCl solutions and liquid foods with different conductivity were used to investigate the thermal effect and temperature rise of samples. Saline gel composed of 3% agar powder and 20% NaCl acted as a coil of conductor for inducing high-level output voltage. The utilization of the saline gel coil significantly improved the power conversion efficiency of the heating unit as well as the heating rate. The results revealed that duty cycle and applied frequency had immediate impact on the efficiency of inner heating. Additionally, the rate of temperature rise was proportional to the conductivity of the sample. The temperature of 200 mL NaCl solution (0.6%) increased from 25 °C to 100 °C in 3 min at 40% duty cycle and 60 kHz of applied frequency, and it was a circulating-flow process. The maximum temperature rise of black vinegar was 39.6 °C in 15 s at 60 kHz and 60% duty cycle, while that of white vinegar was 32.2 °C in 30 s under same conditions, whereas it was a continuous-flow process. This novel heating system has realized the inner heating of liquid samples.


2021 ◽  
Author(s):  
Hassan A. H. Alzahrani

Abstract Copper dioxide (CuO) nanoparticles and Multiwall carbon nanotubes (MWCNTs) filled poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) blend matrix (50/50 wt%) based polymer nanocomposites (PNCs) (i.e., PVA/PVP:(15-x)CuO(x)MWCNTs for x=0,1,5,7.5, 10,14, and 15wt%) have been prepared employing the solution-cast method. The morphologies of these PNCs are semicrystalline, according to an X-ray diffraction investigation. The FTIR, SEM, and AFM measurements of PNCs were used to investigate the development of the miscible mix, polymer-polymer and polymer–nanoparticle interactions, and the influence of CuO and MWCNTs nanofillers on the morphology aspects on the main chain of PVA/PVP blend. The nanofiller dispersion signposting for x=14 wt% nanoloading in the PVA–PVP blend matrix significantly enhances the crystalline phase, diminishing the optical energy gap to 2.31eV. The DC conductivity values augment with the upsurge in nanofiller level for maximum x=14wt%. The dielectric and electrical characteristics of these PNCs are investigated for an applied frequency range from 1kHz to 1 MHz. The enhancement in the nanofiller level upto x=14wt% in the PVA/PVP matrix leads to the development of percolating network through the PNCs. These factors boost the dielectric permittivity values substantially, owing to the decrease in the nano-confinement phenomenon. The rise in applied frequency reduces dielectric permittivity and impedance values and enhances ac electrical conductivity. These PNCs having good dielectric and electrical characteristics can be used as frequency tunable nanodielectric material in electronic devices.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Manas Singh ◽  
Ying Ying Lim ◽  
P. Chinnamuthu

AbstractThis paper reports the catalyst-free coaxial TiO2/Ge-nanowire (NW) heterostructure synthesis using the glancing angle deposition (GLAD) technique integrated into an electron beam evaporator. The frequency and voltage dependence of the capacitance–voltage (C–V) and conductance–voltage (G/ω–V) characteristics of an Ag/TiO2-NW/Ge-NW/Si device over a wide range of frequency (10 kHz–5 MHz) and voltage (− 5 V to + 5 V) at room temperature were investigated. The study established strong dependence on the applied frequency and voltage bias. Both C–V and G/ω–V values showed wide dispersion in depletion region due to interface defect states (Dit) and series resistance (Rs). The C and G/ω value decreases with an increase in applied frequency. The voltage and frequency-dependent Dit and Rs were calculated from the Hill-Coleman and Nicollian–Brews methods, respectively. It is observed that the overall Dit and Rs for the device decrease with an increase in the frequency at different voltages. The dielectric properties such as dielectric constant ($$\upepsilon$$ ϵ ′), loss ($$\upepsilon$$ ϵ ″) and loss tangent (tan δ) were determined from the C–V and G/ω–V measurements. It is observed that $$\upepsilon$$ ϵ ′, $$\upepsilon$$ ϵ ″ decreases with the increase in frequency. Therefore, the proposed MOS structure provides a promising alternative approach to enhance the device capability in the opto-electronics industry.


2021 ◽  
Vol 7 (1) ◽  
pp. 010305
Author(s):  
Natalia Rodenko ◽  
Valentina Zhukova ◽  
Tatyana Vasilieva ◽  
Vladimir Glushchenkov ◽  
Irina Belyaeva

The study aims at the Fourier spectra of an antibiotic exposed to a high-intensity pulsed magnetic field. The applied frequency was f = 40 kHz, with a number of pulses n = 1, at intensities of the pulsed magnetic field H = 0.09 × 106 А/m, Н = 0.50 × 106 А/m, Н = 0.82 × 106 А/m. It was assumed that under the conditions of the pulsed magnetic field there might be a change in the structure of the drug molecule. The research has revealed that an increase in the pulsed magnetic field power leads first to a decrease in the intensity of the band in the Fourier spectrum, and then to its increase. In addition, changes were recorded in the amide group of benzylpenicillin sodium salt molecules depending on the intensity of the pulsed magnetic field applied to the antibiotic.


2020 ◽  
Vol 56 (4) ◽  
pp. 1441-1449
Author(s):  
Khalid Rmaydh Muhammed ◽  
Alex Scrimshire ◽  
Iasmi Sterianou ◽  
Anthony M. T. Bell ◽  
Paul A. Bingham

AbstractPure (BNT) and iron-doped bismuth sodium titanate (Fe-BNT) ceramics were produced according to the formula Bi0.5Na0.5Ti1−xFexO3−0.5x, where x = 0 to 0.1. The addition of Fe2O3 enables decreasing the sintering temperature to 900 °C in comparison with 1075 °C for pure BNT, whilst also achieving lower porosities and greater densities. This is attributed to oxygen vacancy generation arising from substitution of Fe3+ onto the Ti4+ site of the BNT perovskite structure, and the resulting increase in mass transport that this enables during sintering. X-ray diffraction (XRD) analysis of Fe-BNT samples shows single-phase BNT with no secondary phases for all studied Fe contents, confirming complete solid solution of Fe. Rietveld refinement of XRD data revealed a pseudocubic perovskite symmetry (Pm-3m), and unit cell lengths increased with increasing Fe content. Scanning electron microscopy (SEM) showed that average grain size increases with increasing Fe content from an average grain size of ~ 0.5 μm in (x = 0) pure BNT to ~ 5 μm in (x = 0.1) Fe-doped BNT. Increasing Fe content also led to decreasing porosity, with relative density increasing to a maximum > 97% of its theoretical value at x = 0.07 to 0.1. The addition of Fe to BNT ceramics significantly affects electrical properties, reducing the remnant polarization, coercive field, strain and desirable ferroelectric properties compared with those of pure densified BNT. At room temperature, a high relative permittivity (ɛ′) of 1050 (x = 0.07) at an applied frequency of 1 kHz and a lower loss factor (tanδ) of 0.006 (x = 0.1) at an applied frequency of 300 kHz were observed by comparison with pure BNT ceramics.


In this paper we have designed solar charge sensor which is used to make our battery efficient. Component is designed on Virtex 6 FPGA family and applied frequency scaling techniques. During the experiment, we have used different SSTL IO families and calculated total power consumption. In our work we have selected class I and class II from SSTL IO family. For the analysis we have used following range of frequency (20GHz, 40GHz, 60GHz and 80GHz). Firstly, we have worked with SSTL2_I and reduced total power consumption by 51.53%, in second experiment we have worked with SSTL2_I_DCI and reduced consumption of power by 47.18%. In third experiment we choose to work with SSTL2_II and reduced 51.58% in total power consumption. In fourth experiment we opted SSTL15 Io standard and downscale the total power consumption by 51.57%. In fifth we have selected SSTL15_DCI and downscale the power consumption by 49.93%. In sixth experiment we set SSTL18_I_DCI IO standard and consumption minimize by 49.20% in total power. At the end we have mark to be worked with SSTL18_II_DCI which is DCI circuit and found 48.78% reduction in total power consumption.


Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 999 ◽  
Author(s):  
Hauke Meeuw ◽  
Valea Wisniewski ◽  
Bodo Fiedler

Dispersion of carbon nanoparticles in epoxy resin is the key factor to adjust the resulting electrical and mechanical properties of the nanocomposite. A profound understanding of the driving forces of standard methods like ultrasonic and mechanical dispersion is necessary. To derive the impact of applied frequency and strain on the resulting dispersion of multi-walled carbon nanotube (MWCNT)-filled epoxy resin, this work addresses the strain and frequency dependency of oscillatory shear flow-induced network changes. Strain- and frequency-sweeps were performed for a wide parameter set with in-line measurement of electrical DC resistance to monitor changes in the MWCNT network. Changes in electrical resistance reveal destruction and formation of the MWCNT network. A fundamental novel finding is the governing dependency of changes in the electrical network on applied shear amplitude. The applied frequency barely induces network changes. Applied shear rates do not correlate with particular network states.


Nanophotonics ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 1373-1385 ◽  
Author(s):  
Norihisa Kobayashi ◽  
Haruki Minami ◽  
Kazuki Nakamura

AbstractIn this review, we describe the investigation of a ruthenium [Ru(II)] complex-based, AC voltage-driven, electrochemiluminescent (ECL) device first. The ECL turn-on response time and intensity were dramatically improved by introducing the AC method. The turn-on response time was speeded up by increasing the applied frequency: 4 ms response time was achieved at 200 Hz, which was much faster than when using the DC method (1.5 s). We also introduced rutile-type titanium dioxide nanoparticles (TiO2NPs) in a Ru(II) complex-based AC-ECL device. The ECL intensity and the lifetimes of the ECL device with TiO2NPs were greatly improved compared to those of the device without nanoparticles. Then we tried to improve photoelectrochemical properties of the Ru(II) complex by combining it with DNA molecules. We fabricated a novel DNA/Ru(bpy)32+hybrid film that could immobilize the ECL-active Ru(bpy)32+onto the electrode surface through electrophoretic migration. The hybrid film contained unique micrometer-scale aggregates of Ru(bpy)32+in the DNA matrix. Surprisingly, by using the DNA/Ru(bpy)32+hybrid film for the ECL device, luminescence could be obtained at frequencies as high as 10kHz, which corresponds to a response time shorter than 100μs.


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