Electromagnetic Probe Research Articles

Measurement of Hydraulic Fracture Aperture by Electromagnetic Induction.

We present a new method for accurately measuring the aperture of a fluid-driven fracture. This method uses an eddy current probe located within a completion tool specifically designed to obtain the fracture aperture in the wellbore at the location where the fluid is injected into the fracture. The probe induces an eddy current in a target object, producing a magnetic field that affects the overall magnetic field. It does not have any limitations with respect to fluid pressure and temperature within a large range, making it unlike other methods. We demonstrate the accuracy and performance of the sensor under laboratory conditions. A hydraulic fracture experiment in a porous sandstone is conducted and discussed. The obtained measurement of the evolution of the fracture inlet aperture by the eddy current probe during the multiple injection cycles performed provided robust information. The residual fracture aperture (after the test) measured by the probe is in line with estimations from image processing of X-ray CT scan images as well as a thin-section analysis of sub-parts of the fractured specimen. The robustness and accuracy of this electromagnetic induction probe demonstrated herein under laboratory conditions indicate an interesting potential for field deployment.

Enhanced Electromagnetic Near Field Probe for Diagnosis and Materials Characterization

Enhanced Electromagnetic Near Field Probe for Diagnosis and Materials Characterization

Hopf-link GaAs-AlGaAs quantum ring under geometric and external field settings

Within the framework of effective mass approximation and with the use of finite element method, we calculate the energy states of an electron in a double toroidal quantum ring with a Hopf link structure. The study includes the influence of externally applied static electric and magnetic fields, and considers different geometric combinations of radii and link positions. We have found that geometric manipulations have significant impact on the energy values and the distribution of electronic probability densities in either one or both linked rings. Similar effects can be achieved with the application of the electromagnetic probes.

Optimal approach for diagnosing peripheral lung nodules by combining electromagnetic navigation bronchoscopy and radial probe endobronchial ultrasound.

Electromagnetic navigation bronchoscopy (ENB) and radial probe endobronchial ultrasound (RP-EBUS) are essential bronchoscopic procedures for diagnosing peripheral lung lesions. Despite their individual advantages, the optimal circumstances for their combination remain uncertain. This single-center retrospective study enrolled 473 patients with 529 pulmonary nodules who underwent ENB and/or RP-EBUS biopsies between December 2021 and December 2022. Diagnostic yield was calculated using strict, intermediate, and liberal definitions. In the strict definition, only malignant and specific benign lesions were deemed diagnostic at the time of the index procedure. The intermediate and liberal definitions included additional results from the follow-up period. The diagnostic yield of the strict definition was not statistically different among the three groups (ENB/Combination/RP-EBUS 63.8%/64.2%/62.6%, p = 0.944). However, the diagnostic yield was superior in the ENB + RP-EBUS group for nodules with a bronchus type II or III and a solid part <20 mm (odds ratio 1.96, 95% confidence interval 1.09-3.53, p = 0.02). In terms of complications, bleeding was significantly higher in the ENB + RP-EBUS group (ENB/Combination/RP-EBUS 3.7% /6.2/0.6%, p = 0.002), but no major adverse event was observed. The combination of ENB and RP-EBUS enhanced the diagnostic yield for nodules with bronchus type II or III and solid part <20 mm, despite a slightly elevated risk of bleeding. Careful patient selection based on nodule characteristics is important to benefit from this combined approach.

The effectiveness of calcium hydroxylapatite-based Implant in eliminating increased sensitivity of teeth

BACKGROUND: Dental hypersensitivity affects up to 57% of the world’s population. In Russia, high demand for treating hyperesthesia was found among patients aged 30–59 years. Despite the large number of studies conducted, understanding of the etiology and proposed treatment methods to eliminate increased sensitivity of teeth, there is still no effective drug to treat this pathology. Current methods do not ensure long-term elimination of hypersensitivity, which substantiates the need to develop new treatment methods. AIM: To determine the effectiveness of the Radiesse implant (Merz North America, USA) in patients with dental hyperesthesia. MATERIALS AND METHODS: Eighty-six patients aged 35–44 years — men and women with dental hyperesthesia — were examined. The condition of periodontal tissues of teeth with hypersensitivity was assessed by clinical examination methods, and an objective assessment of dental hypersensitivity (tactile impact — TV) was carried out using an electromagnetic device Yeaple Probe (XininX Research Inc., USA). RESULTS: Dental hypersensitivity after a single injection of the Radiesse implant steadily decreases compared to its initial values. CONCLUSIONS: Dental hypersensitivity after a single injection of the Radiesse implant steadily decreases compared to its initial values (p 0.05). Effective reduction of dental hypersensitivity when using Radiesse (Merz North America, USA) lasts for more than 6 months in contrast to the effect of standard treatments.

Signatures of vacuum birefringence in low-power flying focus pulses

Vacuum birefringence produces a differential phase between orthogonally polarized components of a weak electromagnetic probe in the presence of a strong electromagnetic field. Despite representing a hallmark prediction of quantum electrodynamics, vacuum birefringence remains untested in pure light configurations due to the extremely large electromagnetic fields required for a detectable phase difference. Here, we exploit the programmable focal velocity and extended focal range of a flying focus laser pulse to substantially lower the laser power required for detection of vacuum birefringence. In the proposed scheme, a linearly polarized x-ray probe pulse counterpropagates with respect to a flying focus pulse, whose focus moves at the speed of light in the same direction as the x-ray probe. The peak intensity of the flying focus pulse overlaps the probe over millimeter-scale distances and induces a polarization ellipticity on the order of 10−10, which lies within the detection sensitivity of existing x-ray polarimeters. Published by the American Physical Society 2024

Reservoir top detection by resistivity logging signals in deviated and horizontal wells: comparative analysis

This research is aimed at finding out the capabilities of an electromagnetic probe with toroidal coils in geosteering problems. Three-dimensional numerical finite-difference modeling of electromagnetic responses was performed for a probe with toroidal coils, for high-frequency electromagnetic logging probe and side logging sondes in two-layer models with varying resistivity contrast and borehole zenith angle. Based on these calculations, the key features of the toroidal coil electromagnetic sounder (ZET), high-frequency electromagnetic logging (VIKIZ) and side logging (BKZ) signals in detecting the boundary before it is crossed are shown. These features make it possible to determine the approach to the roof of the collector using the signals ZET, VIKIZ and BKZ.

A Hierarchical Classification Method for High-accuracy Instruction Disassembly with Near-field EM Measurements

Electromagnetic (EM) fields have been extensively studied as potent side-channel tools for testing the security of hardware implementations. In this work, a low-cost side-channel disassembler that uses fine-grained EM signals to predict a program's execution trace with high accuracy is proposed. Unlike conventional side-channel disassemblers, the proposed disassembler does not require extensive randomized instantiations of instructions to profile them, instead relying on leakage-model-informed sub-sampling of potential architectural states resulting from instruction execution, which is further augmented by using a structured hierarchical approach. The proposed disassembler consists of two phases: (i) In the feature-selection phase, signals are collected with a relatively small EM probe, performing high-resolution scans near the chip surface, as profiling codes are executed. The measured signals from the numerous probe configurations are compiled into a hierarchical database by storing the min-max envelopes of the probed EM fields and differential signals derived from them, a novel dimension that increases the potency of the analysis. The envelope-to-envelope distances are evaluated throughout the hierarchy to identify optimal measurement configurations that maximize the distance between each pair of instruction classes. (ii) In the classification phase, signals measured for unknown instructions using optimal measurement configurations identified in the first phase are compared to the envelopes stored in the database to perform binary classification with majority voting, identifying candidate instruction classes at each hierarchical stage. Both phases of the disassembler rely on a four-stage hierarchical grouping of instructions by their length, size, operands, and functions. The proposed disassembler is shown to recover ∼97–99% of instructions from several test and application benchmark programs executed on the AT89S51 microcontroller.

Heavy quark drag and diffusion coefficients in the prehydrodynamic QCD plasma

Kinetic and chemical equilibrations play important roles in the formation of the quark-gluon plasma (QGP) in relativistic heavy-ion collisions (HICs). These processes further influence the production of hard and electromagnetic probes in HICs, in particular, the thermalization of heavy quarks, which are produced at an extremely early time before the formation of the QGP. I calculate the drag and diffusion coefficients of heavy quarks in the prehydrodynamic quantum chromodynamic (QCD) plasma with the state-of-the-art QCD effective kinetic theory (EKT) solver. The time, momentum, and angular dependencies of these coefficients for gluon and quark contributions are presented separately, showing the effects of isotropization and chemical equilibration from the QCD plasma. I also provide a simple formula to estimate the heavy quark drag and diffusion coefficients, as well as its energy loss, within the prehydrodynamic plasma at different coupling strengths based on the attractor theory. Finally, I discuss the validity of these estimations with leading-order calculations and leading-logarithmic rescaling factors. Published by the American Physical Society 2024

Electromagnetic probes in heavy-ion collisions

Electromagnetic probes such as photons and dileptons (l+l−) are a unique tool to study the space-time evolution of the hot and dense matter created in heavy-ion collisions, since they are emitted at all stages of the collision with negligible final-state interactions. In this article, the latest results on soft photon (real and virtual) production in heavy-ion collisions are presented.

HADES Overview

In this contribution we present results from Au+Au collisions at √SNN = 2.42 GeV as well as Ag+Ag collisions at √SNN = 2.42 and 2.55 GeV measured by HADES. We focus on three different observables: electromagnetic probes, collective and bulk-matter phenomena and strangeness production which are discussed in the following.

Open channel velocity field investigation for hydrokinetic power generation

The paper presents an experimental study of a velocity field in an open channel. The study of water flow in an open channel is complicated due to the influence of various factors and different variables. Some of the variables affecting the flow parameters include the height of the water column, the width of the channel, the length of the channel, the slope of the channel, and the conditions of the channel bed. The investigated open channel is used for experimental research of kinetic turbines, and the flow speed in the channel is in the range of 0.1-0.3 m/s. The low velocity values in the channel are driven by the operation of the kinetic water turbines in real-world conditions. When describing the test channel, the influence of several boundary conditions has been taken into account, such as protrusions between the measurement sections, the water level, and disturbing effects. Results for the velocity fields determined in five sections of the test open channel are given. A turbine and an electromagnetic probe were used for the experiments. A comparison between the results obtained with the two measuring instruments under the same flow conditions in the test channel is made. The results for the velocity variation in the test sections for the maximum velocity in the channel are presented. At this maximum water velocity, the test channel maintains a water level of approximately 150 mm. The experimental data is also illustrated graphically, along with the velocity fluctuations along the channel centreline. The results obtained provide an idea of the expected velocity fields in the measurement open channel and the relative magnitude of the fluctuations in the different measurement sections.

Quantitative and Qualitative study of the human body effect on the Electromagnetic Probe at 5G and 6G frequencies

The work presented in this paper aims to quantify and qualify the effect of the human body on the dosimeter probe of the electromagnetic field at the 5G and 6G frequencies of mobile networks, in particular in the millimeter wave band. A homogeneous voxel and another heterogeneous representing the human body model have been analyzed under FEKO for exposure in the far zone. The results obtained show that, for all frequencies of our study and the two models of the human body, (1) the frequency of the reflected wave is double that of the incident wave, (2) the relative error due to the presence of the human body close to the dosimeter probe is 75% in the case of an overestimation and also for an underestimate, (3) the position of the first maximum of the electric field (inversely the minimum of the field H) is located at a distance equal to λinc/2 of the incident wave and the second minimum of the field E (inversely the maximum of the field H) at a distance of 3λinc/2 and finally that the maximum and minimum values of the field E and the field H are independent of the frequency of the incident wave.

Research on Electromagnetic Sensing Detection Technology for Non-Destructive Testing Applications

Abstract Nondestructive testing technology, as an indispensable part of modern industrial production, is of great significance for guaranteeing product quality, improving production efficiency, and ensuring production safety. This paper is based on nondestructive testing and electromagnetic sensing detection technology research. The study first adopts ACFM detection to analyze the sensitivity of the surface defect parameters of the material to be detected, and based on the analysis of the magnetic circuit of the electromagnetic sensing structure, to build a mathematical model of ACFM and electromagnetic coupling probe, and then through the magnetic method of non-destructive testing on the material cracks in the detection of the signal effect of the study. The results show that the amplitude of the response signal increases with the increase of the defect angle from 0 to 7 ms, reaching a maximum value of 0.24–0.26 around 6 ms. The amplitude of the response signal decreases with the decrease of the defect angle from 7 to 14 ms and reaches a minimum value of −0.16–0.18 around 14.5 ms. The amplitude of the detection signal is related to the depth of the crack and the length of the surface defect of the steel sheet specimen. The crack depth and surface defect length of the steel plate specimen influence the detection signal’s magnitude. When the defect depth and surface length of the steel plate specimen are 1.5 mm, the detection signal value is weak, and the noise on the surface of the steel plate specimen has a significant effect on the detection signal. Promoting the development and application of NDT technology is greatly aided by the results of this paper.

Numerical convergence of electromagnetic responses with the finite-amplitude method

The response of a nucleus to an electromagnetic probe is a key quantity to simulate photabsorption or photodeexcitation processes. For large calculations at the scale of the entire mass table, this response can be estimated by linear response theory. Thanks to the introduction of the finite-amplitude method (FAM), calculations are computationally efficient. In this paper, we investigate in more details the convergence of FAM calculations of the response function as a function of the parameters controlling the numerical implementation of the theory. We show that the response is much less sensitive to the details of the single-particle basis than, e.g., Hartree-Fock-Bogoliubov calculations.

Electromagnetic probes for critical fluctuations of phase transitions in dense QCD

We study how the dilepton production rates and electric conductivity are affected by the phase transition to color superconductivity and the QCD critical point. Effects of the soft modes associated with these phase transitions are incorporated through the photon self-energy called the Aslamazov- Larkin, Maki-Thompson, and density-of-states terms, which are responsible for the paraconductivity in metallic superconductors. We show that anomalous enhancements of the production rate in the low energy/momentum region and the conductivity occur around the respective critical points.

Pre-equilibrium Photon and Dilepton Production

We use QCD kinetic theory to compute photon and dilepton production in the chemically equilibrating out-of-equilibrium quark-gluon plasma created in the early stages of high-energy heavy-ion collisions. We derive universal scaling functions for the pre-equilibrium spectra of photons and dileptons. These scaling functions can be used to make realistic predictions for the pre-equilibrium emission and consequently establish the significance of the preequilibrium phase for the production of electromagnetic probes in heavy-ion collisions.

Asymmetric calibration method on a back‐to‐back double‐loop differential magnetic field probe

AbstractThe asymmetric calibration method is a very interesting technology for differential output probes. It has been proven that the asymmetric calibration method (ACM) can broaden the application scenarios of the electromagnetic field dual probe. However, ACM is not verified on a back‐to‐back double‐loop differential magnetic field probing system. This paper calibrates a back‐to‐back double‐loop differential magnetic field probing system by inserting a connector for creating an asymmetry using ACM. The calibration results show that ACM can be used to calibrate an asymmetric back‐to‐back double‐loop differential magnetic field probing system. The calibration results are further verified by measuring the standing wave magnetic field, and the verification results show that the asymmetric calibration method is effective in eliminating the asymmetry of the back‐to‐back double‐loop differential magnetic field probing system and the work frequency band reaches up to 12 GHz.

Development of Multifunctional Detection Robot for Roller Coaster Track.

Recent advances in roller coasters accelerate the creation of complex tracks to provide stimulation and excitement for humans. As the main load-bearing component, tracks are prone to damage such as loose connecting bolts, paint peeling, corroded sleeper welds, corroded butt welds, reduced track wall thickness and surface cracks under complex environments and long-term alternating loads. However, inspection of the roller coaster tracks, especially the high-altitude rolling tracks, is a crucial problem that traditional manual detection methods have difficulty solving. In addition, traditional inspection is labor-intensive, time-consuming, and provides only discrete information. Here, a concept of the multifunctional detection robot with a mechanical structure, electrical control system, camera, electromagnetic ultrasonic probes and an array of eddy current probes for detecting large roller coaster tracks is reported. By optimizing the design layout, integrating multiple systems and completing machine testing, the multifunctional roller coaster track detection robot exhibits outstanding performance in track appearance, thickness and crack detection. This study provides great potential for intelligent detection in amusement equipment, railcar, train and so on.

Systematics of mean resonance spacing and average radiative width from random forest regression

The interaction of a nucleus with photons plays a key role in understanding a competition in nuclear reactions. The photon strength function (PSF) gives the average response of a nucleus to an electromagnetic probe. In this study, an estimation is performed of the mean resonance spacing and average radiative width of 22 nuclei in the range A = 46 – 90. The calculations for this analysis are done in TALYS. In addition, a machine-learning driven approach for determining experimentally obtained model parameters from the neutron/proton and mass number is given. A reasonable agreement within the uncertainties is achieved between the model dependent calculations, using TALYS, and results from random forest regression.