High Intensity Electromagnetic Radiation Research Articles

СИСТЕМАТИЧЕСКИЙ АНАЛИЗ ВЛИЯНИЯ ЭЛЕКТРОМАГНИТНОГО ИЗЛУЧЕНИЯ НА ЭКСПРЕССИЮ ГЕНА ТЕПЛОВОГО ШОКА ПРИМЕНИТЕЛЬНО К ЗАДАЧАМ КОСМИЧЕСКОЙ МЕДИЦИНЫ

Scientific publications were used to undertake systematic analysis of the effects of electromagnetic radiation (EMR) on heat shock gene expression in various bio-objects. International normative documents assume that high intensity EMR (100 µWatt/cm2) causes expression of the heat shock gene and ensuing biological consequences. In Russia, the flux energy data level is taken to be 10 µWatt/cm2. Term "data level" means that the EMR bio-effect is not thermal by nature. However, Russian national standard GOST R 50804-95 containing the general medical-engineering requirements to cosmonaut's environment in a piloted spacecraft sets the maximum admissible level at 1000 µWatt/cm2 within the EMR band of 0.3–300 GHz. Systematic analysis of the EMR effects within this band did not reveal expression of the heat shock gene. The investigation should be proceeded with the focus on the EMR non-heat bio-effects.

In situ monitoring of wire and arc additive manufacturing by digital image correlation: a case study

This paper presents a case study of in situ monitoring during wire and arc additive manufacturing (WAAM) process by using digital image correlation (DIC). A feasibility study is carried out aiming at proposing a suitable experimental set-up for in situ measurements during a WAAM process. In this work a stainless steel AISI316L was used to manufacture parallelepiped with nominal dimensions of 130 × 25 mm. The issues related to high-intensity electromagnetic radiation and melted metal projections with regard to image acquisition were addressed. The in situ evolution of the strain field generated in the part during the manufacturing process are shown and discussed. The results show that the horizontal strain component (εxx) presents higher values than the vertical strain component (εyy). The spatial and temporal strain evolution were then analysed at given locations. Strain gradient patterns were clearly observed near the layers underlying material deposition during the process. These results shown the feasibility of using in situ DIC monitoring during the WAAM process.

Damage to the cornea of the eye when exposed to high-intensity electromagnetic radiation of the radio frequency range

An experimental assessment of the clinical manifestations of corneal injuries of the rabbit-eyed eyes closed under the influence of high-intensity electromagnetic radiation (EMR) in the microwave range was carried out. Similar studies have been conducted when exposed to high-intensity EMR ultrahigh frequency (UHF) on the open eye of a rabbit. Dose- and frequency-dependent changes in the cornea of the rabbit eye exposed to EMR frequencies of 3.97 GHz and 1.27 GHz with an average energy flux density (EFD) of 1 W/cm2 were revealed. It has been established that a high-intensity direct short-term exposure to a microwave EMF can lead to damage to even a closed eye. Radiation of the UHF range, which is close in intensity and exposure, in addition to direct damage to the cornea of the open eye, causes slight damage to the external structures of the open paired eye, which is not directly affected. The aforementioned necessitates the development of means and methods of individual protection of the organ of vision of personnel for protection against short-term exposure to powerful electromagnetic radiation of the radio frequency range.

Research on several test issues of electromagnetic radiation susceptibility for electronic equipment

According to the practical problem that some electronic equipments still exist electromagnetic incompatibility phenomenon in training and fighting stage after passing the normal electromagnetic compatibility test required by National Military Standard of China, on the basis of systematically analyzing the technical requirements and test methods in the current military standard, considering the technology accumulation of our research team on the electronic information equipment electromagnetic environment effects in recent years, the influence the several conditions on the electronic information equipment electromagnetic radiation susceptibility test results were discussed. These conditions contain not searching the sensitive receiving direction of the equipment under test(EUT), lacking of electromagnetic radiation susceptibility test in in-band frequency, multi-source radiation causing remarkable reduction of the susceptibility threshold of the EUT and so on. On the basis of the discussion, the measures and suggestions which can solve the above related problems were given. The development tendency of the high intensity electromagnetic radiation effect test technology and the complex electromagnetic environment adaptability evaluation technology for electronic equipment were discussed.

PANDORA, a new facility for interdisciplinary in-plasma physics

.PANDORA, Plasmas for Astrophysics, Nuclear Decays Observation and Radiation for Archaeometry, is planned as a new facility based on a state-of-the-art plasma trap confining energetic plasma for performing interdisciplinary research in the fields of Nuclear Astrophysics, Astrophysics, Plasma Physics and Applications in Material Science and Archaeometry: the plasmas become the environment for measuring, for the first time, nuclear decay rates in stellar-like condition (such as 7Be decay and beta-decay involved in s-process nucleosynthesis), especially as a function of the ionization state of the plasma ions. These studies will give important contributions for addressing several astrophysical issues in both stellar and primordial nucleosynthesis environment (e.g., determination of solar neutrino flux and 7Li Cosmological Problem), moreover the confined energetic plasma will be a unique light source for high-performance stellar spectroscopy measurements in the visible, UV and X-ray domains, offering advancements in observational astronomy. As to magnetic fields, the experimental validation of theoretical first- and second-order Landé factors will drive the layout of next-generation polarimetric units for the high-resolution spectrograph of the future giant telescopes. In PANDORA new plasma heating methods will be explored, that will push forward the ion beam output, in terms of extracted intensity and charge states. More, advanced and optimized injection methods of ions in an ECR plasma will be experimented, with the aim to optimize its capture efficiency. This will be applied to the ECR-based Charge Breeding technique, that will improve the performances of the SPES ISOL-facility at Laboratori Nazionali di Legnaro-INFN. Finally, PANDORA will be suitable for energy conversion, making the plasma a source of high-intensity electromagnetic radiation, for applications in material science and archaeometry.

Effects of Simulated Mobile Phone Electromagnetic Radiation on Fertilization and Embryo Development

ABSTRACTThis study investigated the effects of 935-MHz electromagnetic radiation (ER) on fertilization and subsequent embryonic development in mice. Ovulating mice were irradiated at three ER intensities for 4 h/day (d) or 2 h/d for three consecutive days; the ova were then harvested for in vitro fertilization to observe the 6-h fertilization rate (6-FR), 72-h morula rate (72-MR), and 110-h blastula rate (110-BR). Compared with the control group, the 6-FR, 72-MR, and 110-BR were decreased in the low ER intensity group, but the differences were not significant; in the mid- and high-intensity ER groups, 72-MR and 110-BR in the 4 h/d and 2 h/d subgroups were decreased, showing significant differences compared with the control group. Moreover, the comparison between 4 h/d and 2 h/d subgroups showed significant differences. Mid- and high-intensity ER at 935 MHz can reduce the fertilization rate in mice, and reduce the blastulation rate, thus reducing the possibility of embryo implantation.

Fiber Bragg Grating Strain Sensor Incorporated to Monitor Patient Vital Signs During MRI

This paper reports on results obtained from monitoring the respiration and cardiac activity of a patient during a magnetic resonance imaging (MRI) survey using an optical strain sensor based on a fiber Bragg grating. The sensor is proposed specifically to acquire ballistocardiographic signals from a patient exposed to high intensity electromagnetic radiation. A Bland-Altman analysis shows the measurements that have a satisfactory accuracy for monitoring purposes, and the relative error is . The method is both noninvasive and safe for the patient. In addition, the sensor does not affect the MRI imaging quality.

Effect of 935-MHz phone-simulating electromagnetic radiation on endometrial glandular cells during mouse embryo implantation

This study examined the impact of 935MHz phone-simulating electromagnetic radiation on embryo implantation of pregnant mice. Each 7-week-old Kunming (KM) female white mouse was set up with a KM male mouse in a single cage for mating overnight after induction of ovulation. In the first three days of pregnancy, the pregnant mice was exposed to electromagnetic radiation at low-intensity (150 μW/cm(2), ranging from 130 to 200 μW/cm(2), for 2- or 4-h exposure every day), mid-intensity (570 μW/cm(2), ranging from 400 to 700 μW/cm(2), for 2- or 4-h exposure every day) or high-intensity (1400 μW/cm(2), ranging from 1200 to 1500 μW/cm(2), for 2- or 4-h exposure every day), respectively. On the day 4 after gestation (known as the window of murine embryo implantation), the endometrium was collected and the suspension of endometrial glandular cells was made. Laser scanning microscopy was employed to detect the mitochondrial membrane potential and intracellular calcium ion concentration. In high-intensity, 2- and 4-h groups, mitochondrial membrane potential of endometrial glandular cells was significantly lower than that in the normal control group (P<0.05). The calcium ion concentration was increased in low-intensity 2-h group but decreased in high-intensity 4-h group as compared with the normal control group (P<0.05). However, no significant difference was found in mitochondrial membrane potential of endometrial glandular cells between low- or mid-intensity groups and the normal control group, indicating stronger intensity of the electromagnetic radiation and longer length of the radiation are required to inflict a remarkable functional and structural damage to mitochondrial membrane. Our data demonstrated that electromagnetic radiation with a 935-MHz phone for 4 h conspicuously decreased mitochondrial membrane potential and lowered the calcium ion concentration of endometrial glandular cells. It is suggested that high-intensity electromagnetic radiation is very likely to induce the death of embryonic cells and decrease the chance of their implantation, thereby posing a high risk to pregnancy.

Metallic wire structures under an intense electromagnetic field

We discuss the limitation of metallic wire structures as absorbers of high intensity electromagnetic radiation due to the large local electrical fields developed at junctions and free ends of the wires. We find that at resonance the breakdown external electric field applied to the body of the wire structure is smaller by several orders of magnitude than the dielectric breakdown field induced at the ends of the wire. We consider the double split ring structure and find that it can offer an enhancement of the Ohmic power absorbed by an order of magnitude over those of single component systems. For multiple connected wire structures we find classes of resonant modes with zero local fields at the junctions but the fields at the free wire ends remain finite.

An efficient method of radiation attenuation through aircraft cooling vents

Some critical avionic systems require cooling air via vents on the side of the aircraft, thus creating leakage points for high-intensity electromagnetic radiation. This paper presents a novel application of high-intensity radiated field (HIRF) shielding using a rectangular waveguide array, while maintaining cooling airflow requirements. Signal attenuation versus frequency and depth of the array has been calculated using closed-form equations. The simulation and measurement results are in good agreement with the calculated values. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 130–132, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20566

Stability analysis of digital linear flight controllers subject to electromagnetic disturbances

High intensity electromagnetic radiation has been demonstrated to be a source of computer upsets in commercially available digital flight control systems. Such upsets can degrade the quality of the control signal ranging from a perturbation error over a few sample periods to a permanent error mode or computer failure. Under these conditions, the primary concern of the control engineer is to insure that the closed-loop system remains stable. A stochastic disturbance model and a set of associated stability assessment tools are introduced for determining stability robustness of a nominal closed-loop system subject to electromagnetic disturbances. The focus is primarily on night control applications, but the methodology is suitable for any application where highly reliable digital control is needed. The technique is demonstrated on a simple test example and on a stabilizing controller for the longitudinal dynamics of the AFTI/F-16 aircraft.

Impact of thermal boundary resistance on laser inclusion damage

The present work rigorously analyzes the effect of thermal boundary resistance (TBR) on laser heating of an inclusion embedded in a nonabsorbing optical medium. The TBR impedes the flow of heat across the inclusion/ medium interface, enhances the inclusion heating rate, and reduces the laser damage threshold. The results indicate that in some cases the damage threshold is only half of that predicted when the boundary resistance is neglected. Both an exact solution and approximate scaling relations are developed that incorporate the TBR. The scaling relations show that when the TBR is considered, the damage threshold can have a stronger dependence on the pulse width than previously predicted. l Many novel applications exist for these lasers including laser material pro- cessing, high temporal and spatial resolution measurements, and laser fusion. One of the biggest obstacles in the appli- cation of these lasers is radiation damage incurred by optical components (windows, prisms, etc.) in the laser system. One laser damage mechanism is the so called inclusion-induced damage model. Essentially, inclusions—physical impurities in an otherwise pure optical component material—absorb high-intensity electromagnetic radiation and convert this ra- diation to thermal energy, causing the inclusion to heat up. As the inclusion temperature increases, the surrounding (host) material attempts to conduct the thermal energy away. If the host material cannot adequately conduct away this thermal energy, and the host or inclusion temperature exceeds some threshold temperature—e.g., the melting temperature of the host material, the vaporization temperature of the particle, or a particle temperature that causes fracture in the host— then permanent damage to the optical component can re- sult.24 Inclusion-dominated damage is particularly prevalent in thin film applications where the inclusion density is much higher than that of the bulk film material.3 In the following, particle refers to the absorbing inclusion embedded within the nonabsorbing (i.e., dielectric) host optical material, which is called the medium. To quantify the damage process, damage thresholds are assigned to optical components that characterize the laser radiation limits the component can safely tolerate without sustaining damage. This work is unique in that the thermal boundary resistance (TBR) between the particle and host medium is incorporated in a laser damage model that predicts the damage threshold of optical media. The TBR increases the heating rate of the inclusion and reduces the damage threshold of the optical material. Also, the TBR effect in-

Frequency Shift in High-Intensity Compton Scattering

In this paper the question "Is there an intensity-dependent frequency shift in the Compton scattering of free electrons by high-intensity electromagnetic radiation?" is clarified. It is proven that if the electron is free, i.e., well separated from the electromagnetic beam before and after the interaction, no intensity-dependent frequency shift arises. If, on the other hand, the electron has been interacting with the electromagnetic wave train a sufficiently long time before the actual observation of a Compton scattering event, an intensity-dependent frequency shift will in fact be present.

Standardization of Strong Electromagnetic Fields

THE possible harmful biological effects of high-intensity electromagnetic radiation have become of practical importance in recent years with the development of high-power radar and communication transmitters1. As a result, several instruments have been designed to measure total flux density in the frequency band 30 Mc./s.−30 Gc./s. (wave-lengths, 10 m.−1 cm.). In general, these devices indicate relative values only, and suitable techniques are therefore required by means of which they can be calibrated. Some comments on this problem are given in this communication.