Electromagnetic Frequency Research Articles

Опыт детализации результатов магнитной съемки археологических памятников электроразведочными методами

Now, the work aimed at extracting maximum information about archaeological objects using geophysical methods is relevant. The possibilities for this give us the integration of various geophysical methods. In 2018–2019, electrical exploration works were carried out at the archaeological site Ust-Tartas mounds (Western Siberia). The sites for these works were selected based on magnetic survey data. The purpose of the research was to obtain additional information on the parameters of archaeological objects and to compare the possibilities of different geophysical methods. Several different magnetic anomalies were chosen for the studies. Methods of electromagnetic frequency sounding, electrotomography and georadiolocation were used. We were able to refine the length, width, depth of objects, and their configuration. The type of objects studied (burial or pit, settlement complex) is defined. The most informative results, which complement the magnetic survey data, are obtained using the electrotomography method.

Multi-objective shape optimization of radio frequency cavities using an evolutionary algorithm

Radio frequency (RF) cavities are commonly used to accelerate charged particle beams. The shape of the RF cavity determines the resonant electromagnetic fields and frequencies, which need to satisfy a variety of requirements for a stable and efficient acceleration of the beam. For example, the accelerating frequency has to match a given target frequency, the shunt impedance usually has to be maximized, and the interaction of higher order modes with the beam minimized. In this paper we formulate such problems as constrained multi-objective shape optimization problems, use a massively parallel implementation of an evolutionary algorithm to find an approximation of the Pareto front, and employ a penalty method to deal with the constraint on the accelerating frequency. Considering vacuated axisymmetric RF cavities, we parameterize and mesh their cross section and then solve time-harmonic Maxwell’s equations with perfectly electrically conducting boundary conditions using a fast 2D Maxwell eigensolver. The specific problem we focus on is the hypothetical problem of optimizing the shape of the main RF cavity of the planned upgrade of the Swiss Synchrotron Light Source (SLS), called SLS-2. We consider different objectives and geometry types and show the obtained results, i.e., the computed Pareto front approximations and the RF cavity shapes with desired properties. Finally, we compare these newfound cavity shapes with the current cavity of SLS.

Industrial Wireless Systems Guidelines: Practical Considerations and Deployment Life Cycle

Industrial wireless has great potential to improve the monitoring and control of various processes and equipment in distributed automation systems because of advances in wireless networks and installation flexibility. However, harsh industrial environments and interference from the crowded electromagnetic frequency spectrum make it challenging for wireless to achieve the required performance. Thus, it is important to understand the benefits of wireless in certain industrial settings, the approach for reliable operations, the technologies to be used, and the best practices for successful deployment.

Electromagnetic modeling and analysis of the tapered differential through glass vias

An analytic model of the tapered differential through glass vias is proposed in this paper. Each expression accounting for the via length, diameter, slope angle and pitch is derived from basic physics and the IMD layer is included, additionally. The RLGC equivalent circuit is verified by comparing the S-parameters resulted from the 3-D full-wave electromagnetic solver High Frequency Simulator Structure (HFSS) and Advanced Design System (ADS). The feature selective validation (FSV) technique is used to as a measure of the comparisons. The proposed model and HFSS results show accordance with each other up to 20 GHz The excellent transmission characteristics of glass substrate reflect from S-parameters, of which the S21 is about the order of magnitude of 10−3 dB and the S11 is lower than −30 dB till 20 GHz. Moreover, the impact of different configuration on transmission coefficient is investigated.

Photon drag of a Bose-Einstein condensate

Kepler's observation of comets tails initiated the research on the radiation pressure of celestial objects and 250 years later they found new incarnation after the Maxwell's equations were formulated to describe a plethora of light-matter coupling phenomena. Further, quantum mechanics gave birth to the photon drag effect. Here, we predict a novel universal phenomenon which can be referred to as quantization of the radiation pressure. We develop a microscopic theory of this effect which can be applied to a general system containing Bose-Einstein-condensed particles, which possess an internal structure of quantum states. By analyzing the response of the system to an external electromagnetic field we find that such drag results in a flux of particles constituting both the condensate and the excited states. We show that in the presence of the condensed phase, the response of the system becomes quantized which manifests itself in a step-like behavior of the particle flux as a function of electromagnetic field frequency with the elementary quantum determined by the internal energy structure of the particles.

Investigation of Human Electromagnetic Radiation Characteristic For Kidney Disease Patients

The human body is shown to have their own radiation that emits at certain frequencies into the space surround the body. The purpose of this paper is to investigate the characteristic of human electromagnetic radiation among kidney disease patients and non-kidney disease participants. The body radiation frequencies are measured using body radiation wave detector at twenty-two points of the human body. The properties of human electromagnetic radiation are evaluated using statistical analysis of dependent t-test of Wilcoxon Signed Rank test and independent t-test of Mann-Whitney U test. Significant results with the Sig. value below 0.05 are shown in lower body, torso, chakra, arm and upper body, thus indicates the characteristic differences of human electromagnetic radiation frequency between kidney disease patients and non-kidney disease participants.

Development of digital control system for medium frequency induction furnaces

Traditional medium frequency induction furnace usually adopts analog circuit, which use the theory of PLL to synchronize the drive signal with the induced current signal, so that the upper and lower devices of each phase leg could be gated simultaneously Besides, some problems appear subsequently such as matching debugging difficulty and high failure rate. This paper describes the effect of the burden on the resonant electromagnetic field and resonant frequency through theoretical analysis and magnet field simulation. Based on this, a control and monitoring system designed by digital passive trigger architecture is proposed, phase locking of which is performed according to the frequency of the system itself, fully ensuring that the thyristor will not be simultaneous. In order to improve the stability of the system, this paper optimizes the inverter output control process. At the same time, a friendly human-computer interaction platform is designed, which can achieve distributed data mining, and improve the quality of the product and find the common problems in the product. Finally, the reliability of the control system is verified by experiments.

Management of Conditions Associated With Aging and Older Adults Using Therapeutic Electromagnetic Energy

Objective: To assess the effectiveness of therapeutic electromagnetic energy in the management of conditions associated with an aging and older adult population. Methods: A systematic review of literature from 2008 to 2018 was completed in PubMed, CINAHL, and Science Direct. We also reviewed sources to identify additional relevant studies. Studies in this review were limited to randomized controlled trials that evaluated the effects of shortwave diathermy or pulsed electromagnetic energy units in treating conditions commonly experienced by adults older than 50 years. Study quality was determined using the Physiotherapy Evidence Database (PEDro) classification scale. Results: Fifteen randomized controlled trials met our search criteria. Multiple pathologies were evaluated with the studies examining treatment effects of knee osteoarthritis (n = 12), frozen shoulder (n = 1), postoperative rotator cuff repair (n = 1), and postmenopausal osteoporosis (n = 1). Of the 12 studies that examined knee osteoarthritis, 2 compared pulsed electromagnetic field to placebo or sham, 2 compared the addition of shortwave diathermy to strengthening activities alone, 3 evaluated shortwave diathermy dosage, 3 compared shortwave diathermy to other modalities, and 2 reviewed the benefits of adding pulsed electromagnetic field to other modalities and exercise. Due to the high degree of variability in protocols and outcome measures among studies, meta-analysis was not appropriate. Studies on knee osteoarthritis reported that the use of pulsed electromagnetic field and shortwave diathermy provides statistically significant improvement in pain and function compared with placebo, sham, or control, although there appears to be no benefit in using either form of electromagnetic radiation in addition to or in place of another modality. It also appears that dosage does not significantly change short-term outcomes. These findings are similar to those identified in other recently published systematic reviews that focused exclusively on knee osteoarthritis. Subjects with shoulder pathologies showed improvements in pain, mobility (range of motion), function, activities of daily living, and pain medication usage with pulsed electromagnetic field or shortwave diathermy. Changes in postmenopausal bone density were similar when pulsed electromagnetic field was compared with medication. Conclusion: Shortwave diathermy and pulsed electromagnetic frequency demonstrate similar clinical benefits as other modalities for improving pain, function, and quality of life in the short-term. Further research is needed to better evaluate the parameters of electromagnetic energy and effects for other conditions commonly affecting aging and older adults and at other treatment sites on the body.

Dynamic-Shift Single- and Double-Negative Refractive Index in a Novel Three-Dimensional Metamaterial

A novel three-dimensional terahertz metamaterial by integrating planar and standup resonators on a sapphire substrate is proposed. This structure shows the capability of dynamic-shifting single- and double-negative refractive index bands under temperature control. When the temperature rises from 160 K to 290 K, the single- and double-negative bands of the metamaterials exhibit blue-shift, which is attributed by the simultaneously tuning of the electromagnetic resonance frequencies of the resonators. If the temperature rises to 300 K, the bianisotropy of the metamaterials increases rapidly, while it performs stable between 160 K and 290 K.

Structural elucidation and magnetic behaviour evaluation of gallium substituted garnet ferrites

Impact of gallium (Ga) on structural, morphological and magnetic properties of yttrium iron garnet (YIG) nano-sized ferrites with nominal composition (Y3GaxFe5-xO12, where x = 0.00, 0.40, 0.80, 1.20, 1.60) has been investigated. The samples were prepared via sol-gel auto combustion route. XRD (X-ray diffraction), FESEM (field emission scanning electron microscopy) and VSM (vibrating sample magnetometer) were used to unfold the structural, morphological and magnetic properties of Ga substituted YIG ferrites. Single phase structure of all samples was confirmed through XRD. Cations distribution such as site radii, hopping bond length, shared and unshared edges of the Ga substituted YIG ferrites were also determined. Physical properties such as X-ray density (Dxrd), bulk density (Dbulk), porosity and lattice parameters were found to increase with increasing Ga concentration. FESEM images represented well crystallized and homogenous grains for YIG whereas porous structures were found for Ga substituted ferrites. The grain size of these samples was found in the nano regime (40–86 nm). Magnetic properties such as magnetic saturation, coercivity, remanence, initial permeability, Bohr magneton and anisotropy constant (K) were calculated from hysteresis loops. However, Yafet and Kittle (Y-K) angles were also calculated. Y-K angles were increased with Ga concentration in YIG nano-sized ferrites. Low coercivity and moderate magnetization suggested the use of these ferrites for electromagnetic microwave absorption and frequency agile antenna for wireless communication. Furthermore, the range of operated frequency in microwave region of these nanoferrites suggests the use of these ferrites for high frequency (S and C bands) applications.

Theory of electromagnetic wave frequency upconversion in dynamic media.

Frequency upconversion of an electromagnetic wave can occur in ionized plasma with decreasing electric permittivity and in split-ring resonator-structure metamaterials with decreasing magnetic permeability. We develop a general theory to describe the evolution of the wave frequency, amplitude, and energy density in homogeneous media with a temporally decreasing refractive index. We find that upconversion of the wave frequency is necessarily accompanied by partitioning of the wave energy into low-frequency modes, which sets an upper limit on the energy conversion efficiency. The efficiency limits are obtained for both varying permittivity and varying permeability.

Estimating the angular dynamics of a fan window stroboscope from noisy quantum image measurements

In this paper, we first formulate the dynamics of the fan motor rotation angle $$\theta (t)$$ in terms of a second-order Ito-stochastic differential equation (s.d.e). The aim is to estimate $$\theta (t)$$ on a real-time basis by taking measurements of the transition probability of a quantum system from one state to another when excited by a quantum image field that passes through the fan stroboscopic window. The quantum image field is modeled as a superposition of creation and annihilation operators modulated by appropriate functions of time, dependent upon the quantum electromagnetic field frequency. This field after stroboscopic windowing excites a 3-D quantum oscillator which causes it to make transitions between two oscillator base states with the Quantum field remaining in a coherent state. The dynamics of the transition probability between two fixed oscillator states is shown to be a component of a $$5\times 1$$ vector that satisfies an s.d.e in which the fan window angle and the fan window angular velocity also form some components. Simulation displays the evolution of these transition probabilities as well as of the fan rotation angle. This s.d.e for the $$5\times 1$$ vector when coupled to a measurement model for the 5th component, namely the transition probability, is directly substituted into the equations for an extended Kalman filter (E.K.F), thereby obtaining real-time estimates of the fan angle in terms of the accumulated data of oscillator transition probability.

Use of various biomarkers to explore the effects of GSM and GSM-like radiations on flowering plants.

Since last decade, GSM (Global System for Mobile Communication) technology has evidently revolutionized our digital world. It uses electromagnetic frequency radiations (EMFr), ranging 850-1900MHz, and is being composed of three main units (i.e., mobile station, access and core networks). GSM technology has significant impact on our daily life as revealed by increased number of mobile users in the world over. The main goal of the present review is to critically revisit the available literature regarding the responses of various flowering plant species towards GSM and GSM-like radiations using physiological, biochemical, molecular and cytological markers using in vitro approaches. Different monocots (tomato, onion, wheat and maize etc.) and dicots (pulses, mustard and flax) have been studied using both GSM mobile phone and GSM simulators. Different studies revealed overall reductions in germination, root-shoot lengths, dry weight, in both dose and time-dependent manners. However, there could be found incline in various parameters at biochemical and molecular levels. Furthermore, there could be found disturbances at cytological levels upon exposure of roots of onion to EMFr radiations. The overall literature review shows the negative effects of GSM and GSM-like radiations on targeted plant species. In order to alleviate the stressful effects of EMFr radiations on plants, in vivo studies need to be done using various cost-effective approaches such as use of biochar and various organic amendments.

Comparative assessment of pulsed electromagnetic fields (PEMF) and pulsed radio frequency energy (PRFE) on an in vitro wound healing model

Comparative assessment of pulsed electromagnetic fields (PEMF) and pulsed radio frequency energy (PRFE) on an in vitro wound healing model

Design of Circle Defected Waveguide with Monopole Antenna

In this paper, the circle DWS with monopole antenna is designed and studied. From previous research studies, there are design of waveguide with metamaterial by using Electromagnetic Bandgap (EBG) and Frequency Selective Surface (FSS). Yet, Defected Waveguide Structure (DWS) is not familiar to design with waveguide which is the motivation of this paper. Meanwhile, the design of waveguide with monopole antenna is not explored widely. The DWS is designed in circle shape with Ultrawideband (UWB) monopole antenna. Several factors are studied on the size, inter element spacing and number of circle DWS towards waveguide. Circle DWS with monopole antenna are analyzed through antenna parameters such as return loss, efficiency, gain and directivity. In overall, the circle DWS with monopole antenna able to operate in wide bandwidth of 8.66GHz which is suitable for UWB applications. It also achieves higher efficiency which is more than -3dB. Highest gain of 7.29dB and directivity of 8.62dBi are achieved at 9GHz and 9.5GHz respectively. The use of DWS improves the gain and directivity of low profile monopole antenna but at the same time still maintaining the its wide bandwidth.

Noise Source Visualization for Small DC Motors Using Current Reference without a Reference Microphone.

Noise and vibration sources from small direct current (DC) motors should be clearly visualized for optimal design of low noise motors. For accurate visualization, relatively good reference measurements at optimal locations are required. For some very small motors, the optimal position for a stationary reference microphone may not be accessible during measurement. However, strategies for small motor noise visualization without using a reference microphone have been developed in this study. Only scanning microphones and current measurements of a small motor were used to visualize sound sources. Scanning microphone signals combined with current measurements were used as moving reference signals. Motor noise visualization results based on different moving reference locations have been estimated and reported. Consistent motor noise visualization results from motor current and different, moving reference locations for the major electro-magnetic force excitation frequencies have been shown. Furthermore, for frequencies with relatively low current amplitude, clear motor noise visualization results have been produced for a moving reference located at the center of the motor. Also, the relationship between motor noise and current has been shown, and motor noise has been reduced by connecting an optimal capacitor to the motor power input.

Multiphysics Pretuning Simulation and Testing of a Prototype 1.5-GHz SRF Cavity

Pre-tuning is one of the main processes during production of a superconducting radio-frequency cavity. Instead of the traditional tuning process in air, we investigate in this study cavity tuning under vacuum. As a test, two elliptical 1.5-GHz cavities are characterized on a tuning station and compared with a finite-element simulation to investigate the tuning mechanism. The cavity must be axially loaded for elastoplastic deformation during the pretuning process and therefore, both the incremental computation and the kinematic-hardening are included to describe the elastoplastic behavior of the deformed cavity. An effective simulation process is applied to the multiphysics computation so that the electromagnetic resonance frequency of a highly deformed cavity can be successfully predicted. Test results on 1.5-GHz copper cavities verify the multiphysics computational results. Both test and numerical results show that the tuned frequency is almost linearly dependent on the residual longitudinal displacement.

Electromagnetic shielding property of duplex magnesium alloy with laminated structure processed by accumulative roll bonding

To solve the gradually serious electromagnetic pollution problem, more and more electromagnetic shielding alloys are designed because of its higher conductivities and better workability. However, the increasing incident electromagnetic frequency with the more powerful energy enhance the electromagnetic wave penetrates ability and relatively weakens the alloys’ shielding properties. Some researches indicate that the shielding material with laminated structure exhibit better shielding property at higher incident electromagnetic frequency. Accordingly, a novel duplex Mg-9Li alloy with laminated structure of 24-1 interfaces of strips for electromagnetic shielding was designed and fabricated by accumulative roll bonding (ARB) up to 4 cycles at ambient temperature. With the analysis of microstructure evolution and bonding mechanism, the relative conductivity and the density of the alloy are decreased from 15.38% to 12.03% and from 100% to 94%, respectively. Such changes are attributed to insulted oxide or contaminant during roll bonding. The shielding effectiveness (SE) of the sheets are increased from 56 dB to 73 dB at 1350 MHz with the increasing of phase interlayers interface through ARB process which can be ascribed to the laminated structure of Mg-Li alloy processed by ARB shielding properties according to shielding mechanism.

Parametric resonance in quantum electrodynamics vacuum birefringence

Vacuum magnetic birefringence is one of the most interesting non-linear phenomena in quantum electrodynamics because it is a pure photon-photon result of the theory and it directly signalizes the violation of the classical superposition principle of electromagnetic fields in the full quantum theory. We perform analytical and numerical calculations when an electromagnetic wave interacts with an oscillating external magnetic field. We find that in an ideal cavity, when the external field frequency is around the electromagnetic wave frequency, the normal and parallel components of the wave suffer parametric resonance at different rates, producing a vacuum birefringence effect growing in time. We also study the case where there is no cavity and the oscillating magnetic field is spatially localized in a region of length $L$. In both cases we find also a rotation of the elliptical axis.

Electromagnetically Enhanced Soft and Flexible Bend Sensor: A Quantitative Analysis With Different Cores

Advantages of soft, flexible materials with developments in refined magnetic actuation can be intertwined for a promising platform to work on a resilient, adaptable manipulator aimed to meet ever-increasing demands in safe regulated medical environments. Taking advantages of these soft magnetic polymers, we propose a novel, soft-squishy and flexible bend sensor by determining the relationship between inductance changes with bending angle. This bend sensor employs flexible wire embedded in a silicone elastomer with the different permeable core. The principle notion is to have a comprehensive analysis of the change in morphology of the sensor with bending angle which can be translated to inductance generated therein. The performance of the sensor is evaluated with various experimental trials while analytical modeling elucidates that the bend angle is linearly proportional to the sensor signal citing R-square value up to 0.9204. The proposed sensor produces the desired output in the electromagnetic frequency range of 8–10 MHz with a tunable sensitivity of 0.418 mV/rad. The sensor is robust enough to stretch up to twice of its original length. The main advantage of this bend sensor is its simple fabrication technique, flexibility, robustness, and economical. Conclusively, this paper on induction based tactile bending sensor is proved to produce robust output and can be extrapolated to sense bending angle using induction principle for the rehabilitative device, wearable robots, and related biomedical applications requiring low cost, soft and flexible operations.