Use Of Electromagnetic Device Research Articles

Bioengineered magnetic graphene oxide microcomposites for bioremediation of chromium in ex situ - A novel strategy for aggrandized recovery by electromagnetic gadgetry

Novel magnetic microcomposites consisting of graphene oxide and iron oxide was synthesized to immobilize metabolically versatile Paracoccus sp. MKU1 and Leucobacter sp. AA7 and tested for the simultaneous adsorption and enhanced biological detoxification of hexavalent chromium (Cr(VI)) from tannery wastewater. This study reports highest chromium adsorption of 272.6 mg/g and 179.3 mg/g with complete reduction of Cr(VI) to Cr(III) by the microcomposites of AA7 and MKU1 from wastewater in a bioreactor (10 L) at large-scale for first time in ex situ. Furthermore, both the microcomposites displayed an enhanced detoxification of tannery wastewater by reducing various physicochemical conditions such as ammonia, nitrate, TDS, fluoride, CaCO3, Ca, Mg, NO3 and SO2 under the permissible limits. Use of electromagnetic device for magnetic microcomposites recovery from bioreactor yielded a maximum of 88% and 80.6% recovery for AA7 and MKU1, respectively. The rate of chromium recuperation achieved following desorption from the microcomposites of AA7 and MKU1 was 90.71% and 93.97%, respectively. Thus, the multifarious benefits including adsorption, metabolic detoxification, recovery, and recuperation by single functional microcomposites seems to be an intriguing and profitable approach for practicing in real-time operations to effectively remove heavy metals from the contaminated wastewater for environmental protection.

Design of EM-artifact-free earphone based on the photoacoustic effect

Electromagnetic interactions between conventional earphones and the electroencephalography (EEG) electrodes used for analyzing brain waves give rise to efficiency problems in neurophysiological studies of auditory perception. Currently used speakers and headphones are electromagnetic devices based on strong magnets. In spite of intensive use of such systems, there has been no effective way to eliminate the electromagnetic artifacts produced by such audio transmitting devices to date. The ability for transferring audible sounds without the use of electromagnetic devices that can affect the EEG signal would open up many innovative possibilities in Audio Technologies. Audible sound transfer over long distances is possible by the photoacoustic effect. In such studies, the modulated optical signal can be converted into an audible signal arising from the absorption of the light energy of relevant molecules. In this study, we propose an earphone based on the photoacoustic effect, and calculated the dB SPL (Sound Pressure Level) values for a spherical cell filled with olive pomace. By the use of the method of Diebold and Westervelt, we theoretically calculated the sound pressure levels for our cell and determined a 60 dB SPL at a sound frequency of 1000 Hz for our preliminary earphone design.

Pneumothoraces Prevented With Use of Electromagnetic Device to Place Feeding Tubes.

A US Food and Drug Administration safety letter warned about the risk for pneumothoraces during feeding tube insertion despite the use of electromagnetic placement devices that provide real-time visualization of feeding tube position. To systematically assess pulmonary placement and pneumothoraces in CORTRAK-assisted feeding tube insertions. CINAHL, MEDLINE, and Cochrane databases were searched for studies of CORTRAK-assisted feeding tube insertion. Thirty-two studies documenting pulmonary placement and/or complications of feeding tube insertion were found. Operators recognized pulmonary placement on insertion tracings during 202 CORTRAK-assisted feeding tube insertion procedures, resulting in the immediate withdrawal of 199 feeding tubes. One pneumothorax was identified later by radiography. Seven pulmonary placements were not recognized by CORTRAK operators at the time of feeding tube insertion, resulting in 2 pneumothoraces. The incidence of pneumothorax for CORTRAK-assisted feeding tube insertions was 0.02% (3 of 17039). Of the feeding tubes inserted into the pulmonary system - either found during or after the procedure -1.4% (3 of 209) resulted in pneumothoraces (as opposed to the 19% to 28% incidence of pneumothorax for blind feeding tube insertions. Operators recognizing pulmonary placement on CORTRAK insertion tracings may have prevented 97% (202 of 209) of feeding tubes from being inserted farther into the respiratory tract. Feeding tube insertion with an electromagnetic placement device is advantageous over blind feeding tube insertion because the operator can recognize pulmonary placement early and withdraw the feeding tube, thus decreasing the risk of pulmonary complications.

Evidence-Based Review and Discussion Points.

Evidence-Based Review and Discussion Points.

Use of Electromagnetic Device to Insert Postpyloric Feeding Tubes in a Pediatric Intensive Care Unit.

The preferred route for providing nutrition in the pediatric intensive care unit is enteral. Placement of postpyloric feeding tubes using an electromagnetic-tipped stylet that emits a signal detected by a device held over the patient's abdomen is effective in adult intensive care units, but has not been well studied in pediatric units. To determine the effectiveness of the electromagnetic device in reducing the numbers of radiation exposures, intrahospital transports, tubes used, and tube placement attempts in the pediatric intensive care unit. Data from a historical control group were compared with data from a prospective intervention group of patients less than 18 years of age and weighing at least 3 kg who required a postpyloric feeding tube in a 23-bed pediatric intensive care unit. Primary outcome was number of radiation exposures. Independent-samples Student t tests were used to compare the 2 study groups for mean equality; Pearson χ2 tests were used to compare categorical data. Statistical testing was 2-sided, and P less than .05 was considered statistically significant. Of 73 children (30 in control group, 43 in intervention group), those in the intervention group had a higher success rate at tube placement (P = .009) and fewer radiation exposures (P = .006), intrahospital transports (P = .004), and tubes used (P < .001). Successful placement of postpyloric feeding tubes by nurse practitioners was safely enhanced using an electromagnetic device. Establishing users' expertise with the device before studying outcomes may improve effectiveness.

An electromagnetic inerter-based vibration suppression device

This paper describes how an inerter-based device for structural vibration suppression can be realized using an electromagnetic transducer such as a linear motor. When the motor shaft moves, a difference of voltage is generated across the transducer coil. The voltage difference is proportional to the relative velocity between its two terminals. The electromagnetic transducer will exert a force proportional to current following the Lorentz principle if the circuit is closed around the transducer coil. If an electronic circuit consisting of a capacitor, an inductance and a resistance with the appropriate configuration is connected, the resulting force reflected back into the mechanical domain is equivalent to that achieved by a mechanical inerter-based device. The proposed configuration is easy to implement and very versatile, provided a high quality conversion system with negligible losses. With the use of electromagnetic devices, a new generation of vibration absorbers can be realized, for example in the electrical domain it would be relatively uncomplicated to synthesize multi-frequency or real time tunable vibration absorbers by adding electrical components in parallel. In addition by using resistance emulators in the electrical circuits, part of the absorbed vibration energy can be converted into usable power. Here an electromagnetic tuned inerter damper (E-TID) is tested experimentally using real time dynamic substructuring. A voltage compensation unit was developed in order to compensate for coil losses. This voltage compensation unit requires power, which is acquired through harvesting from the vibration energy using a resistance emulator. A power balance analysis was developed in order to ensure the device can be self sufficient. Promising experimental results, using this approach, have been obtained and are presented in this paper. The ultimate goal of this research is the development of autonomous electromagnetic vibration absorbers, able to harvest energy, convert it into usable power, and use it for vibration control and health monitoring.

An electromagnetic vibration absorber with harvesting and tuning capabilities

This paper describes the development of an electromagnetic vibration absorber (EVA) with energy recovery and frequency tuning control capabilities. The essential component of the EVA is an electromagnetic transducer, interfacing between electrical and mechanical domains, connected to an external electrical circuit. So far, the use of electromagnetic devices in vibration-control applications has been driven by energy-harvesting applications. In these works, the electromagnetic transducer acts as a damper in the mechanical domain by connecting a resistance across the terminals of the device. By emulating the resistive components, some of the power that would have been dissipated in the resistor can be converted into usable power. The use of electromagnetic devices also opens the door (i) to the synthesis of more complex networks in the electrical domain, most of them impractical or too complicated to be synthesized mechanically and (ii) to the development of frequency tuning networks. We consider the possibility of using an EVA along with a resistance emulator to give a self-powered adaptive EVA. We explore the switching in of different elements across the terminals of the electromagnetic transducer in order to be able to derive new low-powered control schemes for better vibration absorption. With the underlying goal to develop high performance, energy-efficient vibration-control devices, a small scale EVA device was tested, coupled with a virtual host structure. The results presented here demonstrate the potential for self-tuning of such a device. Copyright © 2015 John Wiley & Sons, Ltd.

Effect of synthesis on structural and magnetic properties of cobalt doped Mn–Zn nano ferrites

A series of Co2+ doped Mn–Zn ferrite ceramics with the formula Mn0.5Zn0.5−xCoxFe2O4 (x=0, 0.25 and 0.50) have been successfully synthesized using polyethylene glycol-assisted co-precipitation and hydrothermal methods. The structural characterization of the samples has been done using room temperature X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD patterns revealed the formation of pure FCC spinel phase without any impurity peaks. SEM showed the uniform, homogenously spherical nanoparticles prepared from controlled reaction of hydrothermal method. Lattice constant found to be smaller for samples prepared from hydrothermal treatment. The average crystallite size of all nanoparticles were estimated using Scherrer’s formula and found to lie between 10–25±3nm with small size distribution of particles prepared by hydrothermal method. Bond length (A–O) and ionic radii (rA) at A-sites are smaller than the bond length (B–O) and ionic radii (rB) at B-sites for sample series prepared by two methods. Magnetic properties were studied using Physical Property Measurement System (PPMS), Quantum Design Vibrating Sample Magnetometer (VSM) option. Magnetic properties including saturation magnetization was higher (65emu/g for x=0.25) for hydrothermal treated samples. The method of preparation influenced the size of particle which in turn has strong affect on magnetic properties of prepared samples. The enhanced magnetic and structural properties of these nano ferrites made them a potential candidate to use in electromagnetic devices.

Broadband diodelike asymmetric transmission of linearly polarized light in ultrathin hybrid metamaterial

We present the underlying theory, the design specifications, and the experimental demonstration of the broadband diodelike asymmetric transmission of linearly polarized light in the near-infrared regime. This result is achieved through the use of a two-layer hybrid metamaterial, composed of an L-shaped metallic particle and a double nano antenna. The experimental results are shown to agree well with the theoretical predictions and the simulated transmission spectra. The realization of the diodelike asymmetric transmission can be attributed to the combination of two independently functioning metallic structures, which are shown to perform their respective function even when shifted away from perfect alignment. This work offers a further step in developing broadband diodelike asymmetric transmission for use in electromagnetic devices.

A Review of Power Harvesting from Vibration Using Piezoelectric Materials

The process of acquiring the energy surrounding a system and converting it into usable electrical energy is termed power harvesting. In the last few years, there has been a surge of research in the area of power harvesting. This increase in research has been brought on by the modern advances in wireless technology and low-power electronics such as microelectromechanical systems. The advances have allowed numerous doors to open for power harvesting systems in practical real-world applications. The use of piezoelectric materials to capitalize on the ambient vibrations surrounding a system is one method that has seen a dramatic rise in use for power harvesting. Piezoelectric materials have a crystalline structure that provides them with the ability to transform mechanical strain energy into electrical charge and, vice versa, to convert an applied electrical potential into mechanical strain. This property provides these materials with the ability to absorb mechanical energy from their surroundings, usually ambient vibration, and transform it into electrical energy that can be used to power other devices. While piezoelectric materials are the major method of harvesting energy, other methods do exist; for example, one of the conventional methods is the use of electromagnetic devices. In this paper we discuss the research that has been performed in the area of power harvesting, and the future goals that must be achieved for power harvesting systems to find their way into everyday use.

Antennas and other electromagnetic applicators in biology and medicine

Medical and biological applications of antennas can be classified into two broad groups: (1) therapeutic and (2) informational (including diagnostics and measurement of material electromagnetic (EM) properties). Most of these applications involve EM coupling into or out of the body which requires a device such as an antenna or other applicator. A common characteristic of many applications is the difficulty of coupling EM energy into the interior of the body without damaging the surface. Rapidly increasing computing power and new developments in numerical EM techniques are expected to have a great impact on the use of EM devices in medicine and biology.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Electromagnetic dosimetry for models of humans and animals: A review of theoretical and numerical techniques

Theoretical dosimetry, i.e., calculation of the electromagnetic (EM) energy absorbed by humans in radiation fields, has become increasingly important as the use of EM devices in our society has increased. Since such calculations are difficult and complicated, a number of EM analysis techniques have been used by researchers in the field to obtain dosimetric data and understanding of absorption characteristics. Both analytical and numerical EM techniques have been applied extensively. In this paper, important techniques are reviewed and significant dosimetric data are summarized. Some important areas of future research in EM dosimetry are discussed.