scholarly journals Comparative studies of ultra-high dilutions of LiCl: impedance spectroscopy in the frequency range of 1kHz to 13MHz

Author(s):  
Adriana Ramos de Miranda
2015 ◽  
Vol 12 (2) ◽  
pp. 13
Author(s):  
Muhamad Faridz Osman ◽  
Karimah Kassim

The coordination complexes of Co(II) and Zn(II) with Schiff bases derived from o-phenylenediamine and substituted 2-hydroxybenzaldehyde were prepared All compounds were characterized by Fourier transform infrared (FTIR) spectroscopy and Nuclear magnetic resonance (NMR) spectroscopy elemental analyzers. They were analyzed using impedance spectroscopy in the frequency range of 100Hz-1 MHz. LI and L2 showed higher conductivity compared to their metal complexes, which had values of 1.3 7 x 10-7 and 6.13 x 10-8 S/cm respectively. 


Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1889
Author(s):  
Sounghun Shin ◽  
Yoontae Jung ◽  
Soon-Jae Kweon ◽  
Eunseok Lee ◽  
Jeong-Ho Park ◽  
...  

This paper presents a reconfigurable time-to-digital converter (TDC) used to quantize the phase of the impedance in electrical impedance spectroscopy (EIS). The TDC in the EIS system must handle a wide input-time range for analysis in the low-frequency range and have a high resolution for analysis in the high-frequency range. The proposed TDC adopts a coarse counter to support a wide input-time range and cascaded time interpolators to improve the time resolution in the high-frequency analysis without increasing the counting clock speed. When the same large interpolation factor is adopted, the cascaded time interpolators have shorter measurement time and smaller chip area than a single-stage time interpolator. A reconfigurable time interpolation factor is adopted to maintain the phase resolution with reasonable measurement time. The fabricated TDC has a peak-to-peak phase error of less than 0.72° over the input frequency range from 1 kHz to 512 kHz and the phase error of less than 2.70° when the range is extended to 2.048 MHz, which demonstrates a competitive performance when compared with previously reported designs.


2005 ◽  
Vol 494 ◽  
pp. 101-106
Author(s):  
B. Škipina ◽  
T. Čajkovski ◽  
M. Davidović ◽  
D. Čajkovski ◽  
V. Likar-Smiljanić ◽  
...  

In our previous work we investigated the conductivity and dielectric relaxation phenomena in heteropoly acids and their salts. In this work, we have studied the conductivity of grains and grain boundaries in compressed powders of 12-tungstophosphoric acid (WPA) salts with univalent and bivalent ions. The method of impedance spectroscopy has been employed in the frequency range from 5 Hz to 500 kHz. We obtained grains and grain boundaries conductivities as well as corresponding activation energies. Grain conductivity in all investigated salts is always higher than the grain boundary conductivity.


Author(s):  
Anatoliy A. Lepeshev ◽  
Alexandr V. Pavlov ◽  
Nikolai A. Drokin

The present study is aimed at obtaining electrically conductive two-component ceramics based on BeO with the addition of micro and nanocrystalline TiO2 powder. The ceramics of the composition (BeO+TiO2) is used in radio-electronic equipment as effective absorbers of microwave radiation and in other areas of modern electronics. The nature of the appearance of electrical conductivity and absorption of the microwave field in (BeO+TiO2) ceramics has not been completely established. The impedance spectroscopy method for the first time investigated the electrical and dielectric characteristics of this ceramics in the frequency range from 100 Hz to 100 MHz, depending on the presence of micro and nano-sized TiO2 phases in the composition of the BeO ceramics. It was established that the static resistance of ceramics with the addition of titanium oxide nanopowder is significantly reduced compared with the resistance of the original ceramics with TiO2 micropowder. It is shown that the real and imaginary components of the dielectric constant of the studied ceramics increase to abnormally large values when the frequency of the effective electric field decreases, and in the high frequency range f ≥ 108 Hz, the process of dielectric relaxation begins, leading to an increase in the dielectric loss tangent. The dielectric characteristics of these ceramic samples under conditions of blocking through conduction are determined


2017 ◽  
Vol 6 (1) ◽  
pp. 26
Author(s):  
Widodo Budi Kurniawan

Telah dilakukan pengukuran tetapan dielektrik kompleks dan besarnya impedansi kapasitor pada material keramik Calcium Copper Titanate dengan struktur material CaCu3Ti4O12 (CCTO) dengan kemurnian 99 % menggunakan metode spektroskopi impedansi terkomputerisasi dalam rentang frekuensi 5 kHz – 120 kHz. Tetapan dielektrik maksimum terukur pada sampel yang disintering dengan suhu 7000C yaitu 745 pada frekuensi 5 kHz dan besarnya impedansi kapasitor maksimum terjadi pada sampel CCTO non sintering yaitu 150434 Ω. Hasil penelitian menunjukkan adanya pengaruh frekuensi terhadap tetapan dielektrik kompleks dan impedansi kapasitor dari material yang diteliti. Kata kunci : spektroskopi impedansi, CaCu3Ti4O12, tetapan dielektrik kompleks dan impedansi kapasitor.   MEASUREMENT OF THE DIELECTRIC CONSTANT CALCIUM COPPER TITANATE (CaCu3Ti4O12) MATERIALS USING COMPUTERIZED IMPEDANCE SPECTROSCOPY  ABSTRACT The measurement of the complex dielectric constant and the magnitude of the capacitor impedances of the ceramic materials Calcium Copper Titanate CaCu3Ti4O12 (CCTO) with purity of 99% has been done by using the method of computerized impedance spectroscopy in the frequency range 5 kHz - 120 kHz. The highest dielectric constant of the material was found to be 745 at 5 kHz in the sample sintered 7000C and the highest impedance of capacitor occured in CCTO sample non sintered that is 150434Ω. The results showed that complex dielectric constant and impedance of the capacitor of the material under study was frequency dependent. Keywords : impedance spectroscopy, CaCu3Ti4O12,complex dielectric constant and impedance of capacitor


2021 ◽  
Vol 2008 (1) ◽  
pp. 012008
Author(s):  
L G Teixeira ◽  
P Bertemes-Filho ◽  
M. Keith Cox

Abstract The consumption of seafood has increased over the last 10 years. This article analyses impedance changes of tilapia (Oreochromis niloticus) sample measured over 36 hours by using electrical impedance spectroscopy (EIS). It was also investigated the correlations between variables in order to predictive models to degradation studies. Measurements were collected every 12 hours in order to verify any change due to deterioration. The results show that measurements in both longitudinal and transverse axes are equivalent and that the sample undergoes gradual variations in the impedance. The first set of data collected in the frequency range from 0.1 to 1,000 kHz showed that resistance varied from 310.9 (@ 0.1 kHz) to 86.8 Ω (@1 MHz) and capacitive reactance varied from -8.6 to 11.5 Ω, respectively. The forth set of data showed a decrease of 79.3% (@0.1 kHz) in the resistance part of the impedance, whereas 98.8% in capacitive reactance at 0.1 kHz. These results might suggest that there was a nutritional loss of the sample over time. Further experiments must be done over a long period of time in order to fully understand the process. EIS might be pointed out as a potential technique for fish shelf live quality control.


2021 ◽  
Vol 10 (36) ◽  
pp. 101-103
Author(s):  
Adriana Ramos de Miranda ◽  
Claudia Takano ◽  
Alvaro Vannucci

Introduction: The Impedance spectroscopy [1] is a technique mainly used to characterize the electrical behavior of solids or liquids samples. This particular technique involves placing the sample of material under investigation between two electrodes (capacitor plates), applying an AC voltage and observing the resulting response across the spectrum of impedance by plotting the real part (Z’) as a function of the imaginary part (Z”) of the impedance. Alternatively, graphs of either the real or the imaginary parts of the impedance can be constructed as a function of the applied voltage frequency. Comparative measurements previously carried out by Miranda et al [2]. have demonstrated clear differences between the impedance values of high dilutions of lithium chloride (LiCl) and the corresponding reference water samples (water which has undergone the same dinamization procedures but without the salt). In this paper the results obtained by applying the spectroscopy of impedance technique in high dilutions of Lycopodium clavatum - Lyc (from 15cH to 30 cH), in comparison to the reference waters, will be presented and discussed. Aims: The objective of this work is to measure the impedance components of both high dilutions of Lycopodium clavatum and reference water samples in the frequency range of 100Hz to 13Mhz, using a successful protocol of sample preparation which has already been used before2. Details of the experimental set-up can be found elsewhere[3]. Methodology: Thirty samples of Lyc solutions and thirty reference water samples were produced using the same preparation and measuring protocol. Both groups of liquid samples were measured for dynamizations ranging from 1cH to 30cH, in accordance to the Hahnemanian dynamization method and following the practice suggested by the Brazilian Homeopathic Pharmacopeia. The Lyc solutions were specifically compared to the reference water samples in the potencies of 15cH, 18cH, 23cH and 30cH. It is important to highlight here that all the Lyc solutions and the corresponding reference water samples measured were prepared from the same lot of initial distilled water and submitted to the same steps of dilution and succussion protocol3. Typically three impedance measurements were carried out for each investigated solution, starting with the highest potency. The sample holder (capacitor cell) used during the experiment was careful and systematically cleaned after each measurement. Results: The results obtained show that by choosing either the real part (Z’) or the imaginary component (Z”) of the impedance, it is possible to clearly differentiate the Lyc solutions from the corresponding reference water samples, for the potencies 15cH, 18cH and 30cH. For the potency 23cH, however, this difference is not very significant, as it can be observed in Figure 1. Conclusion: Impedance spectroscopy has demonstrated itself to be a powerful and sensitive technique for the physical characterization of Lycopodium clavatum in high dilutions. The differences obtained for the LiCl dynamizations and the corresponding pure water samples are noteworthy. Also, the results exhibit a non-monotonic behavior over the process of dynamization, indicating that the possibility of contamination during the samples manipulation can be ruled out.


2015 ◽  
Vol 12 (2) ◽  
pp. 13
Author(s):  
Muhamad Faridz Osman ◽  
Karimah Kassim

The coordination complexes of Co(II) and Zn(II) with Schiff bases derived from o-pheny/enediamine and substituted 2-hydroxybenza/dehyde were prepared All compounds were characterized by Fourier transform infrared (FTIR) spectroscopy and Nuclear magnetic resonance (NMR.) spectroscopy elemental analyzers. They were analyzed using impedance spectroscopy in the frequency range of 100 Hz - 1 MHz. L1 and L2 showed higher conductivity compared to their metal complexes, which had values of 1.3 7 x 10-7 and 6.13 x 10-8 S/cm respectively.


2013 ◽  
Vol 789 ◽  
pp. 16-20
Author(s):  
Viktor Vekky Ronald Repi ◽  
Azwar Manaf

We have investigated of composite (1-x)Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15 / xLa0.7Ba0.3MnO3 by conventional ceramic method. The sturcture of composite and complex impedance are carried out by XRD, SEM and Impedance Spectroscopy. With changing the weight ratio from x=0; 0.3; 0.5 and x=1 the phase exhibit the composite behavior. Very interestingly, for the case of the case of weight ratio x=0.5 and 0.7 showed the complex impedance with xemicircle pattern in frequency range from 1 KHz to 1 MHz.


Lab on a Chip ◽  
2017 ◽  
Vol 17 (15) ◽  
pp. 2674-2681 ◽  
Author(s):  
Charles A. E. Little ◽  
Nathan D. Orloff ◽  
Isaac E. Hanemann ◽  
Christian J. Long ◽  
Victor M. Bright ◽  
...  

On-chip microwave calibrations are used to characterize the electrical-double layer response for saline solutions in microfluidic channels over an extremely broad frequency range.


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