Impedance Spectroscopy applied to the study of high dilutions of Lycopodium clavatum

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.

Ionic Conductivity of Ce0.91Ca0.09O2 as an Electrolyte for Intermediate Temperature Solid Oxide Fuel Cells

The search for new cost-effective electrolyte materials for IT-SOFC towards its mass scale commercialization has gained momentum in recent years. The Ca- doped ceria having composition Ce0.91Ca0.09O2 was prepared using the facile conventional solid-state method. The structural and electrical properties of low sintered ceramic samples have been characterized by X-ray diffraction (XRD), UV–VIS diffuse reflectance spectroscopy (DRS) and A.C. impedance technique respectively. The oxide ion conductivity was measured between the temperatures 573 K−973 K in air. The obtained results showed that total conductivity is mainly dependent on the grain boundary effect. The nanocrystalline Ce0.91Ca0.09O2 exhibited the high total ionic conductivity of 7.36  103 S cm1 at 973 K with a lower activation energy of 0.96 eV. The obtained results highlight the use of cost-effective dopant in ceria lattice to develop commercially viable electrolyte materials for IT-SOFC.

An Experimental Study of Damage Detection on Typical Joints of Jackets Platform Based on Electro-Mechanical Impedance Technique

Many methods have been used in the past two decades to detect crack damage in steel joints of the offshore structures, but the electromechanical impedance (EMI) method is a comparatively recent non-destructive method that can be used for quality monitoring of the weld in structural steel joints. The EMI method ensures the direct assessment, analysis and particularly the recognition of structural dynamics by acquiring its EM admittance signatures. This research paper first briefly introduces the theoretical background of the EMI method, followed by carrying out the experimental work in which damage in the form of a crack is simulated by using an impedance analyser at different distances. The EMI technique is used to identify the existence of damage in the welded steel joints of offshore steel jacket structures, and Q345B steel was chosen as the material for test in the present study. Sub-millimetre cracks were found in four typical welded steel joints on the jacket platform under circulating loads, and root average variance was used to assess the extent of the crack damage.

A Low-Noise, High-Gain, and Small-Size UWB Mixer Utilizing Negative Impedance Technique and Source Input Method

This paper presents an ultra-wideband (UWB) down-conversion mixer with low-noise, high-gain and small-size. The negative impedance technique and source input method are applied for the proposed mixer. The negative impedance achieves the dynamic current injection and increases the mixer output impedance, which reduces the mixer flicker noise and increases its conversion gain. The source input method allows the input matching networks to be cancelled, avoiding the noise and loss introduced by the matching resistors, saving the chip area occupied by the matching inductors. The proposed mixer is designed in 45-nm SOI process provided by GlobalFoundries. The simulation results show a conversion gain of 11.4–14.3 dB, ranging from 3.1 to 10.6 GHz, a minimum noise figure of 9.8 dB, a RF port return loss of less than −11 dB, a port-to-port isolation of better than −48 dB, and a core chip area of 0.16 × 0.16 mm2. The power consumption from a 1 V supply voltage is 2.85 mW.

A PZT-based electromechanical impedance method for monitoring the moisture content of wood

Purpose At present, piezoelectric impedance technology has been used in the study of wood damage monitoring. However, little effort has been made in the research on the application of piezoelectric impedance system to monitor the change of wood moisture content (MC). The monitoring method of wood MC is used by piezoelectric impedance technique in this study. Design/methodology/approach One piezoceramic transducer is bonded to the surface of wood specimens. The MC of the wood specimens increases gradually from 0% to 60% with 10% increments; the mechanical impedance of the wood specimen will change, and the change in the mechanical impedance of the structure is reflected by monitoring the change in the electrical impedance of lead zirconate titanate. Therefore, this paper investigates the relationship between wood MC change and piezoelectric impedance change to verify the feasibility of the piezoelectric impedance method for monitoring wood MC change. Findings The experiment verified that the real part of impedance of the wood increased with the increase of wood MC. Besides, the damage index root mean square deviation is introduced to quantify the damage degree of wood under different MC. At the same time, the feasibility and validity of this experiment were verified from the side by finite element simulation. Finally, MC monitoring by piezoelectric impedance technique is feasible. Originality/value To the best of the authors’ knowledge, this work is the first to apply piezoelectric ceramics to the monitoring of wood MC, which provides a theoretical basis for the follow-up study of a wide range of wood components and even wood structure MC changes.