Increase In Resistivity Research Articles

Purification of phage for therapeutic applications using high throughput anion exchange membrane chromatography

As cases of multidrug resistant bacterial infections increase, scientists and clinicians around the world are increasingly turning to bacteriophages as alternatives to antibiotics. Even though our understanding of phage has increased significantly since the early days of its discovery, over a century ago, the currently used tools and technologies for phage purification for therapeutic applications are severely limited. Bacteriophages are produced by bacterial cultures, and impurities such as endotoxins must therefore be removed before clinical use. We present an anion exchange bind-and-elute membrane chromatographic method for purifying T7 bacteriophage from Escherichia coli culture supernatant that removes undesirable impurities, while ensuring a high viable phage count in the purified product. Our method does not involve the use of chemicals such as organic solvents and caesium chloride that could typically leave residual toxicity in the final product. It also does not require expensive equipment, such as an ultracentrifuge. Using our method, that is based on an in-house designed membrane module, 65% of viable T7 phage was recovered, and up to 94% endotoxins could be removed. The method, which took approximately 15 min, is rapid and scalable, and produces quite pure bacteriophage samples in a single step. It therefore potentially represents a major improvement over the status quo, and shows the way ahead for streamlining phage manufacturing for therapeutic use.

Geostress effect on resistivity and its relevant correction method

For reservoirs with abnormally high pressure and high geostress, formation resistivity can be greatly affected. This increase of resistivity resulting from high stress causes errors in the identification of reservoir fluids. In order to investigate the effect of stress on resistivity, resistivity measurement was conducted simultaneously with triaxial testing to obtain rock resistivity under high temperature and high pressure. The changes of resistivity and resistivity increasing coefficient with horizontal differential stress and minimum horizontal stress were revealed from experiments. Besides, field data were analyzed to show the main influencing factors of formation resistivity under reservoir conditions. In addition, a new resistivity correction model for high geostress formation was derived in this work. The interpretation results are in good agreement with well testing data in the Keshen area of the Tarim oilfield, China.

Low-resistivity molybdenum obtained by atomic layer deposition

A novel atomic layer deposition (ALD) process was developed for low-resistivity molybdenum (Mo) from molybdenum dichloride dioxide (MoCl2O2) and atomic hydrogen (at-H). A wide ALD window of self-limiting growth was observed between 150 and 450 °C. No film deposition occurred with molecular hydrogen (H2), demonstrating the necessity to have at-H to efficiently reduce the MoCl2O2 precursor. At 350 °C and above, the film composition was determined at approximately 95 at. % of Mo and 3.5 at % of oxygen (O), with trace amounts (i.e., <1 at. %) of carbon (C), chlorine (Cl), hydrogen (H), and nitrogen (N). The growth per cycle (GPC) was roughly 0.022 nm/cycle. No substrate selectivity or pronounced nucleation delay was observed on silicon (Si), silicon dioxide (SiO2), silicon nitride (Si3N4), silicon carbide (SiC), aluminum oxide (Al2O3), hafnium dioxide (HfO2), and low-k dielectric (SiOC). Film uniformity and conformality were ±5% and ±10%, respectively, while resistivity approached a bulk value of 18.6 μ Ω cm at 24 nm. At 250 °C and below, increased levels of oxygen (up to 33 at. % at 150 °C) and chlorine (2.7 at. % at 150 °C) were detected in the film. This trend coincided with an increase in the GPC, a change in optical properties, a decrease in film density and crystallinity, and an increase in resistivity. While self-limiting growth was observed through the entire ALD window of 150–450 °C, the temperature (T) range for depositing low-resistivity Mo deposition was narrower at T ≥ 250 °C.

Effects of shrinkage-reducing admixtures and expansive agents on the self-sensing behavior of nanomodified cement-based materials

Shrinkage control is needed to ensure an appropriate installation of cementitious sensors used in the Structural Health Monitoring of concrete elements. However, the effects of shrinkage-reducing admixtures (SRAs) and expansive agents (EAs) on the self-sensing properties of the cementitious sensors is still unknown. Therefore, the present work evaluated the effects of a SRA and EAs based on calcium oxide (CaO) or calcium sulfoaluminate (CSA) on the shrinkage behavior, microstructure, self-sensing response and compressive strength of mortars containing carbon black nanoparticles (CBN). The SRA provided shrinkage reductions up to 47.4%. CaO-based EA and CSA-based EA provided an expansive behavior. The admixtures caused increases in electrical resistivity and gauge factor up to 37.1% and 71.0%, respectively. In contrast, they did not cause statistically significant changes in stress sensibility and compressive strength. A microstructural analysis suggested that portlandite and ettringite crystals provided by the inclusion of EAs caused interruptions in conductive paths inside the mortars, which decreased contact conduction mechanisms and increased the amount of insulating tunneling gaps between CBN, enhancing the gauge factor of the materials. Therefore, shrinking control admixtures were found to be promising alternatives to enable the dimensional compatibility between cement sensors and old concrete elements, and increase the self-sensing properties of smart cementitious composites.

Manipulation of spin–orbit torque and Dzyaloshinskii-Moriya interaction by varying Mn concentration in Pt1-xMnx/Co bilayer

Reducing critical current density (JC) of current-driven magnetization switching via power-efficient spin–orbit torque (SOT) is a key challenge in spin-based memory and logic devices. The Pt1-xMnx alloy shows prospect for enhancing the damping-like SOT efficiency (ξDL) while maintaining relatively low resistivity and power consumption. In this work, we investigated the Mn concentration x dependence of ξDL in Pt1-xMnx/Co bilayer and observed a nonmonotonic variation with the maximum ξDL ≈ 0.25 appearing around x = 0.2. The increase of the Pt1-xMnx layer resistivity is the main contribution to the enhancement of ξDL. Mn atoms doped in Pt not only modulate ξDL originating from the spin Hall effect of the Pt1-xMnx layer, but also affect the interfacial phenomena at the Pt1-xMnx/Co interface. We find that the related interfacial Dzyaloshinskii-Moriya interaction (DMI) is also tunable by x with the maximum appearing around x = 0.15. The significantly reduced JC of Pt1-xMnx/Co bilayer is mainly due to the enhancement of ξDL and the attenuation of effective perpendicular magnetic anisotropy energy density. Meanwhile, Pt1-xMnx/Co bilayer maintains low power consumption and necessary thermal stability. Our work highlights the potential of alloying Pt with Mn as a valuable means to achieve high-performance SOT spintronic devices.

Thermal analysis of the influence of harmonics on the current capacity of medium‐voltage underground power cables

AbstractIn this article, an algorithm is proposed and used to study the influence of harmonics on the behavior of medium‐voltage underground cables in flat formation. The proposed algorithm is a thermal model based on the heat equilibrium of the thermal circuit nodes of the medium‐voltage cable system. The impact of harmonics on the temperature rise of the cable elements and the cable capacity is evaluated in this article. Also, the impact of harmonics on the derating factors of cable for different soil types is presented. Finally, the measurement of temperatures of cable cores is carried out experimentally and compared with the calculated results to validate the proposed algorithm. One of the algorithm merits is that several harmonic percentages can be taken into account for each cable phase individually, and the heat exchange between the cable phases and their sheath is also taken into consideration. From the obtained results, it is illustrated that the presence of harmonics has a remarkable influence on the cable core temperature; mainly, harmonics of the third and fifth orders may lead to dry zone formation around the cable. It is also observed that the presence of harmonics has an important influence on the cable current, especially when it is buried in soil that has high thermal resistivity during the summer season (suction tension = ∞). In summer, the cable core temperature reached 152.162°C, 139.053°C, and 133.375°C when lime, sand, and silty sand, respectively, are used as backfill materials, rather than 90°C in the normal operating condition of the 11 kV three‐phase single‐core cable. It is observed also that with the increase of the soil thermal resistivity, the ratio of /) reached about 1.2 times at 2.5 K m/W soil thermal resistivity. In addition, it is also observed that the impact of harmonics leads to a percentage reduction in the derating factor of the cable center phase by 11.88%–12.37% depending on the composition of the backfill materials.

High room temperature magnetoresistance in La0.9Sr0.1Mn1-yZnyO3 epitaxial films

Developing large room temperature magnetoresistance materials has been a major hotspot for a few last decades due to its importance in the practical applications in magneto-resistive random access memory, and it remains a challenge. Here, La0.9Sr0.1Mn1-yZnyO3 (LSMZO) films have been grown on SrTiO3 substrates by magnetron sputtering, showing excellent quality of epitaxy. Upon increasing Zn content, the reduction of Curie temperature (TC) and metal-insulator transition temperature (TMI) is observed, accompanied by the increase of coercive field and room-temperature resistivity. Analysis on the fraction of Mn3+ and Mn4+ indicates that Zn2+ substitution at Mn site results in a higher Mn4+ fraction departing from the optimum value and hence a weaker double-exchange interaction by replacing more Mn3+. Besides that, ionic radius mismatch induced internal strain and substrate induced tensile strain also play a part. Most significantly, the enhanced magnetic disorder gives rise to an increase of intrinsic magnetoresistance around room temperature in LSMZO (y = 10%) film, and a large magnetoresistance of 18.4% is obtained under 0.3 T at 280 K in this sample. Our research provides a simple and effective approach to achieve a large room temperature magnetoresistance in Mn site doped manganite epitaxial films.

Effect of induced defects on conduction mechanisms of noble-gas-implanted ScN thin films

Noble-gas implantation was used to introduce defects in n-type degenerate ScN thin films to tailor their transport properties. The electrical resistivity increased significantly with the damage levels created, while the electron mobility decreased regardless of the nature of the ion implanted and their doses. However, the transport property characterizations showed that two types of defects were formed during implantation, named point-like and complex-like defects depending on their temperature stability. The point-like defects changed the electrical conduction mode from metallic-like to semiconducting behavior. In the low temperature range, where both groups of defects were present, the dominant operative conduction mechanism was the variable range hopping conduction mode. Beyond a temperature of about 400 K, the point-like defects started to recover with an activation energy of 90 meV resulting in a decrease in resistivity, independent of the incident ion. The complex-like defects were, therefore, the only remaining group of defects after annealing above 700 K. These latter, thermally stable at least up to 750 K, introduced deep acceptor levels in the bandgap resulting in an increase in the electrical resistivity with higher carrier scattering while keeping the metallic-like behavior of the sample. The generation of both types of defects, as determined by resistivity measurements, appeared to occur through a similar mechanism within a single collision cascade.

Adaptation of multipurpose tractors to row spaces of cotton crops

In the Republic of Uzbekistan, cotton cultivation is carried out on row spacings of 60; 76 and 90 cm. The machine-tractor parks of cotton-growing farms are equipped with agricultural machines designed for these inter-row spacings and they are aggregated by tractors with gauges designed for them. Such a variety of tractor gauges creates the problem of mismatch between the gauge and row spacing when moving from one row spacing to another, increases the variety of spare parts and narrows the scope of their use only within one type of row spacing. The discrepancy between the gauge of serial universal row-crop tractors and the cultivated row spacing leads to damage to the plant and compaction of the soil in the area where its root system is located. Overconsolidation of the soil by more than 1.1 g/cm3 leads to a slowdown in plant growth and development, an increase in soil resistivity during subsequent tillage operations and, most importantly, a decrease in crop yield. Studies have established that, despite the variety of designs of known devices used to adjust the track, they change the track stepwise and in an insufficient range, as a result of which the tractor does not fit into the row spacing. To eliminate the shortcomings of the known methods for adjusting the track, a device has been developed for adapting the tractor running system to work on different row spacings. The developed device allows, without the use of attachments or interchangeable axle shafts and their casings, to accurately adapt the tractor’s running system to the aisle of crops cultivated by it, thereby eliminating the existing shortcomings of serial universal row-cultivator tractors. The article provides a description of the proposed technical solution and the method of its application.

Electrical conductivity and heating performance of hybrid steel fiber-reinforced SCC: The role of high-volume fiber and micro fiber length

Recently, it has become very popular to develop electrically conductive concrete composites for active deicing and snow-melting of transportation infrastructure. These composites should have stable electrical conductivity and a uniform heating performance, as well as high mechanical and durability properties, for a sustainable solution. In this context, the main motivation of this study is to develop an electrically conductive hybrid steel fiber reinforced self-compacting concrete (HSFR-SCC) composite for ice and snow removal applications. The electrical conductivity and heating performance of self-compacting concrete (SCC) mixtures having different fiber volumes (1.00, 1.25, and 1.50%) and the combination of macro steel fiber with micro steel fibers having lengths of 13 and 6 mm as single and hybrid were experimentally investigated for the first time. For this purpose, a total of ten SCC mixtures were designed, one of which was non-fiber Control, the others had steel fiber volumes of 1.00, 1.25, and 1.50% and different fiber combinations. Workability (slump-flow, T500 and J-ring) tests on HSFR-SCC mixtures were performed with reference to EFNARC. Then, mechanical (compressive and flexural strengths), electrical resistivity, and heating performance tests of 90-day HSFR-SCC samples were carried out. Before the electrical resistivity and heating performance tests, HSFR-SCC samples were kept in an oven at 105 ± 5 °C for 24 h to measure their most critical state (dry) performance. Moreover, using multiple linear regression analysis, empirical equations and contour plots were developed to predict the electrical resistivity and temperature increase values of HSFR-SCC samples depending on fiber volumes and combinations. Considering the experimental results, electrically conductive HSFR-SCC mixtures with satisfactory workability and high strength were obtained. The addition of various volumes and combinations of steel fiber to SCC significantly improved the electrical conductivity and heating performance of the concrete, while the mixtures with hybrid fiber were the best for all fiber volumes. As for the different micro fibers added to the HSFR-SCC mixtures, the 13 mm length micro steel fiber was much more effective in improving the electrical resistivity and heating performance of the samples compared to the 6 mm length micro steel fiber. Also, it was found that the fiber-reinforced index of electrically conductive HSFR-SCC samples could be 0.87 for effective and efficient electrical conductivity.

Simultaneous enhancement of magnetic properties and electric resistance of hot-deformed Nd-Fe-B magnets by doping insulating nano-diamonds

The combination of high coercivity and resistivity is a strong requirement for permanent magnets to resist thermal demagnetization under complex operating conditions. However, this still remains a challenge for conventional strategies, which always sacrifice the maximum energy product as the coercivity or resistivity increases. In this work, we report a unique strategy of introducing only 0.1 wt% of insulating nano-diamonds (NDs) into the hot-deformed Nd-Fe-B magnets to significantly and simultaneously improve both magnetic properties (Hci, Br, (BH)max and Hk/Hcj) and resistivity. In particular, the coercivity increased by 60% from 746 to 1193 kA/m. Further microstructure observations indicate that this exceptional effect stems from NDs can effectively inhibit the formation of coarse grains and optimize the distribution of Nd-rich phases, ensuring a strong pinning effect to enhance hard magnetic performance. Meanwhile, the presence of additional grain boundaries and NDs can also lead to higher resistivity by preventing the movement of free electrons. Our work provides a distinctive strategy for interface modification with excellent comprehensive performance in permanent magnets.

Full-wave electromagnetic analysis of lightning strikes to wind farm connected to medium-voltage distribution lines

This paper studies the voltages developed on a wind turbine (WT) and a medium-voltage distribution line (MVDL) connected to a wind farm subjected to lightning strikes and located on frequency-dependent (FD) soils. The ground potential rise (GPR), voltages at the blade tip and on phase conductors of the MVDL are calculated using the full-wave electromagnetic software XGSLab® employing the rigorous Partial Element Equivalent Circuit (PEEC) method. The wind farm comprises four wind turbines with interconnected grounding systems using cables buried in resistivity soils of 1,000 and 5,000 Ω m. The voltages are computed for the first positive impulse (FPI) of 100-kA 10/350μs and for the subsequent negative impulse (SNI) of 50-kA, 1/200μs. Results have shown that voltage peaks increase notably as the soil resistivity increases. When the WTs are assumed, oscillations in the GPR waveforms for the SNI occur due to the multiple reflections between the blade and the turbine’s base. However, the voltages for the FPI present smooth time-domain responses. Furthermore, the overvoltages developed at the MVDL are significantly dependent on the soil resistivity and lightning current waveform.

Realizing ultrahigh energy-storage density in Ca0.5Sr0.5TiO3-based linear ceramics over broad temperature range

In the realm of energy storage, there is an exigent need for dielectric materials that exhibit high energy storage density (Wrec) and efficiency (η) over wide temperature ranges. Linear dielectrics exhibit superior breakdown strength (Eb) compared to ferroelectrics, yet their utility is restricted by low polarization. Here, an ultrahigh Wrec up to 7.92 J/cm3 and η ≈ 94.3% are realized in (Ca0.5Sr0.5)1-1.5xSmxTiO3 ceramic with ultrafast discharge time (t0.9 = 20 ns) which is one of the best energy storage performances recorded linear ceramics. By employing the charge balance method, the production of oxygen vacancies (VO··) can be prevented, leading to improved insulation. The creation of A-site vacancies serves to enhance the breakdown field strength. Furthermore, the incorporation of Sm3+ effectively limits the thermal activation of oxygen vacancies at elevated temperatures, ultimately resulting in an increase in bulk resistivity. The results also unveil the outstanding stability across a wide range of temperatures (20 °C–140 °C) and frequencies (1 Hz–500 Hz). Consequently, this study provides significant insights into enhancing Eb and attaining high-energy storage capacitors.

Resistivity and damage of coal under cyclic loading and unloading

The stability of the coal in underground coal mining can be reduced greatly by mining activities and seepage water. Studying the failure and damage evolution of water-saturated coal under cyclic loading is therefore of great importance. Conducting single-axis equal-amplitude cyclic loading and unloading tests of water-saturated coal, this paper studied the resistivity response and analyzed the relationship between resistivity and strain field with Digital Image Correlation (DIC) in coal cyclic loading. The damage in coal cyclic loading was quantitatively characterized by the damage variables and damage constitutive equations based on electrical resistivity. The results show that the response of resistivity and DIC is regular and complementary. In the loading stage, the strain field has an opposite trend to the resistivity, which decreases as the load force increases; In the unloading stage, the resistivity increases correspondingly, but the shearing strain decreases. The above responses correlate with the sample failure: as the number of cycles increases, the sample's internal damage accumulates, and the resistivity and strain increase accordingly. The two damage variables and the trend of plastic strain are in good agreement. The damage constitutive model's calculation agrees with the experimental results. The resistivity method is able to objectively describe the whole damage process of saturated water coal under constant amplitude cyclic loading, thus contributing to the understanding of the damage mechanism of coal and rock subjected to complex stresses, which is of great practical significance and value to the safe and efficient production of coal mines.

THE INFLUENCE OF COBALT ON DENSITY AND ELECTRICAL RESISTIVITY OF Al–Ni–Co–Ce ALLOYS IN CRYSTALLINE AND LIQUID STATES

In this work were studied density (by gamma-absorption method) and electrical resistivity (by contactless method in rotating magnetic field) of Al–Ni–Co–Ce glass-forming alloys with different ratios of transition metals. It was found the existence of a wide two-phase zone was established and jump-like changes in properties at solidus and liquidus temperatures. Increasing of cobalt content from 2 to 4 at % leads to 2% decrease of density and 3% increase of electrical resistivity in crystalline and liquid states. Temperature coefficients of change in properties were calculated. Density hysteresis was detected, which occurs when melts are overheated above 1350 K. This fact is related to the disintegration of large-scale microheterogeneities that exist in melts during heating. It is shown that these results can be used to optimize the process of obtaining rapidly hardened alloys.

Process-Gas-Influenced Anti-Site Disorder and Its Effects on Magnetic and Electronic Properties of Half-Metallic Sr2FeMoO6 Thin Films

Anti-site disorder, arising due to the similar size of Fe and Mo ions in Sr2FeMoO6 (SFMO) double perovskites, hampers spintronic applicability by deteriorating the magnetic response of this double perovskite system. A higher degree of anti-site disorder can also completely destroy the half-metallicity of the SFMO system. To study the effects of different process gas conditions on the anti-site disorder, we have prepared a series of SFMO thin films on SrTiO3 (001) single-crystal substrate using a pulsed laser deposition (PLD) technique. The films are grown either under vacuum or under N2/O2 partial gas pressures. The vacuum-grown SFMO film shows the maximum value of saturation magnetization (MS) and Curie temperature (TC), signaling the lowest anti-site disorder in this series. In other words, there is a long-range Fe/Mo-O-Mo/Fe ferrimagnetic exchange in the vacuum-grown thin film, thereby enhancing the magnetization. Further, all the SFMO films show a semiconducting state with a systematic increase in overall resistivity with the increased anti-site disorder. The electrical conduction mechanism is defined by the variable-range hopping model at low temperatures. Raman spectra show a weak Fano peak, suggesting the presence of electron–phonon coupling in SFMO thin films. These results show the significance of the process gas in causing anti-site disorder, tuning the degree of this disorder and therefore its influence on the structural, magnetic, electrical, and vibrational properties of SFMO thin films.

Unusual role of ZnO nanoparticles in enhancing the thermoelectric performance of GeTe

ZnO nanoparticles were incorporated into the GeTe samples. Unexpectedly, the ZnO nanoparticles reacted with the GeTe phase to produce ZnTe and Ge impurities. Ge precipitates promoted self compensation in GeTe, which in turn reduced the Ge vacancies and decreased the carrier concentration. The resulting increase in the Seebeck coefficient led to a higher power factor, despite an increase in the electrical resistivity. Due to the optimized power factor and a lower carrier thermal conductivity, the average zT increased from 0.64 for the pure GeTe to 0.79 for GeTe + 0.5 wt.% ZnO. Additionally, irreversibility of the reaction between GeTe and ZnO during the high-temperature thermoelectric measurements emphasizes importance of the proper sequence for the property measurements; the Hall data should be recorded once the thermopower and electrical conductivity were measured to high temperatures.

Ion-Selective Scattering Studied Using the Variable-Energy Electron Irradiation in the Ba0.2K0.8Fe2As2 Superconductor.

Low-temperature variable-energy electron irradiation was used to induce non-magnetic disorder in a single crystal of a hole-doped iron-based superconductor, Ba1-xKxFe2As2, x = 0.80. To avoid systematic errors, the beam energy was adjusted non-consequently for five values between 1.0 and 2.5 MeV when sample resistance was measured in situ at 22 K. For all energies, the resistivity raises linearly with the irradiation fluence suggesting the creation of uncorrelated dilute point-like disorder (confirmed by simulations). The rate of the resistivity increase peaks at energies below 1.5 MeV. Comparison with calculated partial cross-sections points to the predominant creation of defects in the iron sublattice. Simultaneously, superconducting Tc, measured separately between the irradiation runs, is monotonically suppressed as expected, since it depends on the total scattering rate, hence on the total cross-section, which is a monotonically increasing function of the energy. Our work experimentally confirms an often-made assumption of the dominant role of the iron sub-lattice in iron-based superconductors.

EXTRAORDINARY MAGNETORESISTANCE OF LASERANNEALED NANO BORON DEPOSITEDON OXIDIZED POROUS SILICON

This study explores the impact of laser annealing on the electrical and magnetic properties of nano boron deposited on oxidized porous silicon (n-B/PSiO2) and its potential for spintronic applications. The Nd: YAG laser was used at varying energies to anneal the n-B thin films. Increasing the laser energy increased grain size and more ordered grain structures. It also increased surface roughness due to forming new grain boundaries and secondary phases. The electrical properties of the material were also affected by the laser annealing, with an increase in forward and reverse current and an increase in electrical resistivity with increased annealing temperature. The study also found that the magnetoresistance of the material increased with increasing laser temperature, attributed to tunnel injection through the thin silicon dioxide layer, and could be up to 7 times higher than non-annealed n-B/PSiO2in a magnetic field. The study highlights the importance of controlling materials’ grain size and structure for their physical and electrical properties. In addition, it provides insights into the electronic properties of n-B/PSiO2and the behavior of charge carriers in a magnetic field.

Detection Performance Analysis of Array Dielectric Dispersion Logging Based on Sensitivity Function

Dielectric logging is a critical method for exploring and developing complex oil and gas reservoirs, such as tight reservoirs, low-resistivity contrast reservoirs, and shale oil and gas reservoirs. The sensitivity function is extended to high-frequency dielectric logging in this paper. The detection characteristics of attenuation and phase shift of an array dielectric logging tool in different modes are investigated, along with the influencing factors such as resistivity and dielectric constant. The results show the following: (1) The symmetrical coil system structure makes the sensitivity distribution symmetrically distributed, and the detection range is more focused. In the same measurement mode, the depth of investigation (DOI) becomes deeper under high resistivity formation, and the sensitivity range oscillates outward when the dielectric constant becomes greater. (2) The DOIs of different frequencies and source spacings cover the radial zone between 1 cm and 15 cm. The detection range has been enlarged to include part of the invasion zones, improving the measurement data’s dependability. (3) With the increase in the dielectric constant, the curve tends to oscillate, and this behavior makes the DOI slightly shallower. Additionally, this oscillation phenomenon is obvious when the frequency, resistivity, and dielectric constant increase, particularly in high-frequency detection mode (F2, F3).