No description available.

The purpose of the study was to examine the relationship between self reported exposure to sources of electromagnetic fields, frontal left and right hemisphere absolute and relative power EEG measurements, and a measure of depression. Thirty-three male undergraduates with varying degrees of EMF exposure assessed by cell phone and computer use were participants in the study. Results indicated that there were significant relationships between long term computer use, indicated by years of use, total Beck Depression Inventory (BDI) scores, and suicidal thoughts or wishes. There were significant positive relationships between both long term and current computer use, indicated by minutes per month, and eyes open delta (,5-3.5Hz) absolute power in both hemispheres. Significant negative relationships were found between computer use and eyes open absolute power and relative power in the 12-15Hz EEG band. Also, significant positive and negative relationships were found between several delta, alpha, and theta absolute power and/or relative power EEG measurements and total and item scores on the BDI.

No description available.

Yes / Employing electromagnetic fields EMFs) in new wireless communication and sensing technologies has substantially increased the level of human exposure to EMF waves. This paper presents a useful insight into the interaction of electromagnetic fields with biological media that is defined by the heat generation due to induced currents and dielectric loss. The specific absorption rate (SAR) defines the heating amount in a biological medium that is irradiated by an electromagnetic field value. The paper reviews the radio frequency hazards due to the SAR based on various safety standards and organisations, including a detailed investigation of previously published work in terms of modelling and measurements. It also summarises the most common techniques utilised between 1978 and 2021, in terms of the operational frequency spectrum, bandwidth, and SAR values. / The European Union’s Horizon 2020 innovation programme under grant agreement H2020- MSCA-ITN-2016 SECRET-722424 and the U.K. Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1 supported this research. This study is also sponsored by the FCT/MEC through national funds and, where applicable, co-financed by the ERDF under the PT2020 Partnership Agreement under the UID/EEA/50008/2020 project. This study is part of the POSITIONII project, which is funded by the European Commission’s Joint Undertaking under the grant number Ecsel-7831132-Postitio-II-2017-IA. Moreover, this paper is also partially funded by British Council “2019 UK-China-BRI Countries Partnership Initiative” programme, with project titled “Adapting to Industry 4.0 oriented International Education and Research Collaboration”. In addition, this project has received funding from Universidad Carlos III de Madrid and the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant 801538.

Electromagnetic fields (EMFs) have been associated with increased incidences of cancer as suggested by epidemiological studies. The in vitro sister chromatid exchange (SCE) technique, radiation-induced micronucleus assay (MN assay), COMET assay, and fluorescence in situ hybridization (FISH) were used in the present study to test the carcinogenic potentiality of extremely low frequency (ELF) EMFs on human peripheral blood lymphocytes. All experiments were performed single blind and used lymphocytes taken from 6 age-matched donors. The SCE experiments were conducted twice: round 1 (R1) and round 2 (R2), in order to determine whether or not the results obtained could be duplicated. Detailed analysis of the SCE results showed that there was a significant increase in the number of SCEs/cell in the grouped experimental conditions compared to the controls in both rounds. Similarly, in the MN assay, a significant increase of mean number of micronucleated CB cells/100 CB cells (Ma) and mean number of micronuclei/100 CB cells (Mb) was observed in the grouped experimental conditions compared to the controls. Moreover, the highest SCE frequency in R1 was 10.03 for a square continuous field, and the SCE frequency of 10.39 for a square continuous field in R2 (albeit a different strength) was the second highest in this latter round. But in the MN assay a square pulsed field with increasing EMF strength showed the greatest effect on the DNA repair system. The COMET assay also showed that both a l m T square field (continuous or pulsed) resulted in significant fragmentation of the DNA. On the other hand, a FISH analysis failed to show any translocations. In the field of EMF research, perhaps the most outstanding question that remains to be answered with certainty is how weak EMFs exert their effects at the molecular level. Various mechanisms are reviewed and evaluated in this thesis. From the results of the research performed in the current study which concentrated on testing and discovering genetic effects, a model is postulated that weak EMFs stimulate the production of free radicals which result in genetic damage. Further extensive research should be conducted to test this hypothesis.

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in ful lment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2015 / During a cloud to ground lightning event a charge centre within the storm cloud is discharged. The discharge of a charge centre within the cloud leads to a change in the electric eld radiated by the charge centre. It is theoretically possible to infer the lightning current from the derivative of the electric eld. It is only possible to infer the lightning current from the electric eld data where the noise is comparatively much smaller than the electric eld data. The changing electric elds for a lightning event that occurred on the 3rd January 2015 13:15:13 were recorded by a at plate electric eld sensor with a passive integrator. The oscilloscope used to capture the electric eld data has a relatively large measurement noise and a low resolution. A low pass digital lter was applied to the recorded electric eld data to reduce the e ects from the high frequency noise. The lightning strokes were recorded by the South African Lightning Detection Network. The Lightning Detection Network data is used to obtain the distance of the lightning event from the sensor, to scale the inferred lightning current. The Lightning Detection Network also provides a lightning peak current measurement to compare to the peak current inferred from the electric eld data. The lightning stroke current was inferred from the electric eld recording for various bandwidths of the low pass lter. Inconsistent changes to the inferred lightning stroke current as the lter bandwidth is changed shows that the frequency components for each stroke di ers. The peak stroke current was not constant for any lter bandwidth range implying that the measurement noise is relatively too large. The case study presented demonstrates that with a relatively large noise magnitude (3 to 4 discrete steps of the digital recording) compared to the electric eld signal (21 discrete steps) it is di cult to accurately infer the lightning current from the electric elds recorded. / MT2017

by Ho Yum Bun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 93-94). / Text in English; abstracts in English and Chinese. / by Ho Yum Bun. / List of Figures --- p.3 / Abstract --- p.9 / Chinese Abstract --- p.10 / Acknowledgement --- p.11 / Chapter 1 --- Introduction --- p.12 / Chapter 1.1 --- Motivation --- p.12 / Chapter 1.2 --- What is Sonoluminescence? --- p.13 / Chapter 1.3 --- The Main Task of this Project --- p.13 / Chapter 1.4 --- Organization of this Thesis --- p.13 / Chapter 2 --- Reviews on One-dimensional Dynamical Cavity Problem --- p.15 / Chapter 2.1 --- Introduction --- p.15 / Chapter 2.2 --- Formulation --- p.15 / Chapter 2.3 --- Moore's R Function Method --- p.18 / Chapter 2.4 --- Mode Expansion Method --- p.19 / Chapter 2.5 --- Transformation method --- p.20 / Chapter 2-6 --- Summary --- p.21 / Chapter 3 --- Numerical Results For One-dimensional Dynamical Cavity Prob- lem --- p.22 / Chapter 3.1 --- Introduction --- p.22 / Chapter 3.2 --- Evolution of a Cavity System --- p.23 / Chapter 3.3 --- Motion of the Moving Mirror --- p.23 / Chapter 3.4 --- R(z) Function --- p.24 / Chapter 3.4.1 --- Construction of R(z) Function --- p.24 / Chapter 3.4.2 --- Numerical R(z) Function --- p.27 / Chapter 3.5 --- Results --- p.27 / Chapter 3.5.1 --- Results with Moore's R(z) Function Method --- p.27 / Chapter 3.5.2 --- Results with the Mode Expansion Method --- p.29 / Chapter 3.5.3 --- Results with the Transformation Method --- p.36 / Chapter 3.6 --- Summary --- p.36 / Chapter 4 --- Spherical Dynamical Cavity Problem --- p.37 / Chapter 4.1 --- Introduction --- p.37 / Chapter 4.2 --- Formulation --- p.37 / Chapter 4.3 --- Motion of a Moving Spherical Mirror --- p.39 / Chapter 4.4 --- Summary --- p.40 / Chapter 5 --- The G(z) Function Method --- p.41 / Chapter 5.1 --- Introduction --- p.41 / Chapter 5.2 --- G(z) Function --- p.42 / Chapter 5.2.1 --- Ideas of Deriving the G(z) Function --- p.42 / Chapter 5.2.2 --- Formalism --- p.42 / Chapter 5.2.3 --- Initial G(z) Function --- p.45 / Chapter 5.3 --- Construction of the G(z) Function --- p.46 / Chapter 5.3.1 --- Case I : l=0 --- p.46 / Chapter 5.3.2 --- Case II : l > 0 --- p.49 / Chapter 5.4 --- Asymptotic Series Solution of G(z) --- p.50 / Chapter 5.5 --- Application to Resonant Mirror Motion --- p.52 / Chapter 5.6 --- Regularization of G(z) --- p.58 / Chapter 5.7 --- Behaviors of the Fields --- p.58 / Chapter 5.7.1 --- z vs tf Graph --- p.61 / Chapter 5.7.2 --- Case 1: l= 0 --- p.61 / Chapter 5.7.3 --- "Case2: l= 1,2" --- p.62 / Chapter 5.7.4 --- Case 3: l= 3 --- p.73 / Chapter 5.7.5 --- Section Summary --- p.73 / Chapter 5.8 --- Summary --- p.73 / Chapter 6 --- Three-dimensional Mode Expansion Method and Transforma- tion Method --- p.75 / Chapter 6.1 --- Introduction --- p.75 / Chapter 6.2 --- Mode Expansion Method --- p.75 / Chapter 6.2.1 --- Formalism --- p.75 / Chapter 6.2.2 --- Application of Floquet's Theory --- p.78 / Chapter 6.2.3 --- Results --- p.80 / Chapter 6.3 --- The Transformation Method --- p.80 / Chapter 6.3.1 --- The Method --- p.80 / Chapter 6.3.2 --- Numerical Schemes --- p.86 / Chapter 6.3.3 --- Results --- p.89 / Chapter 6.4 --- Summary --- p.89 / Chapter 7 --- Conclusion --- p.90 / Chapter 7.1 --- The One-dimensional Dynamical Cavity Problem --- p.90 / Chapter 7.2 --- The Dynamical Spherical Cavity Problem --- p.91 / Chapter 7.3 --- Numerical Methods --- p.91 / Chapter 7.4 --- Further Investigation --- p.92 / Bibliography --- p.93

Nanoscale materials usually present strikingly different properties in comparison with their bulk counterparts, such as quantum size effects, surface plasmon resonance (SPR). To explore new properties as well as for novel applications, nanomaterials are being extensively investigated. This project investigates the interactions of electromagnetic fields with nanoscale materials, particularly gold nanoparticles (GNPs), over a wide range of frequency bands, including static field, 261 kHz, 13.56 MHz, 2.45 GHz, millimetre wave, THz, and the visible light. Especially, the efforts have been devoted to the study of heating effect of GNPs in association with potential biomedical applications. To explain the electromagnetic heating of GNPs, dielectric properties of GNP dispersions has been studied from 100 MHz to 20 GHz, as well as in the millimetre wave and THz ranges. The static field induced effects on the size distribution of GNPs has also been examined using ultra-violet spectroscopy and correlated to SPR. It has been revealed that purified GNPs cannot increase the specific absorption rate substantially at whichever frequency points of 261 kHz, 13.56 MHz, or 2.45 GHz. However, a greater temperature rise has been observed in the impurified GNP dispersions compared to deionisedwater, after 10 min RF treatment at 13.56 MHz. The measurements on dielectric properties show that impurified samples have much higher effective conductivity than that of deionised-water, while the conductivity change of purified ones is very small and not detectable within the measurement accuracy. This observation supports that the heating effect of GNP dispersions is mostly contributed by the impurities and disproves that GNPs can increase the specific absorption rate significantly. The magnetic field heating at 261 kHz suggests that GNPs have very weak magnetic properties. It has been found that a static field can change the size distribution of GNPs. Up to 2 THz, it is measured that the dielectric properties of GNP dispersions have no convincing change compared to deionised-water, implying that the electromagnetic heating of GNP below 2 THz may be insignificant. In addition, it is confirmed that GNPs have strong absorption in the visible light range due to SPR.

No description available.

As mobile phone connections approach two billion worldwide and become steadily more available and affordable, demands for scientific studies on the effect of such EMFs on human functioning similarly increase. The current thesis systematically investigated the effects of acute mobile phone exposure on human brain activity and performance using an in-vivo approach. The research question comprised the following parts: First, is human neural function sensitive to acute mobile phone exposure? Second, if so, what processes are affected? Third, if so, do these neural changes affect gross measures of performance or behaviour? A review of the previous literature found that there was some, but not conclusive evidence that mobile phone exposure affects neural function and some aspects of human performance, and that the studies in question required replication with reliable and realistic dosimetry, double-blinding and additional technical tests to ensure that the experimental set-up was free of artefact contamination. A pilot study was conducted to provide an indication of possible future results, assist in the formation of hypotheses for the main study, and highlight what technical issues required attention before the main study could begin. Results of the pilot study indicated that EMFs emitted by GSM900 mobile phones may alter human brain activity during an auditory task, particularly in proximity to the phone. Both early sensory and later more cognitive ERP components were significantly altered during active compared to sham exposure. Results also suggested that mobile phone exposure may hinder human performance, with longer RTs during the active exposure relative to the sham exposure. However, due to the small sample size of the pilot investigation and questions remaining as to possible technical limitations of the study, these results were treated with caution and used primarily in the formation of future hypotheses for the larger experimental study. Subsequent technical tests provided improvement and validation of the experimental set-up and exposure delivery system, and ensured that future research would be free from such technical limitations. These tests included the characterisation of spectral emissions by the test phone; ensuring that EMFs emitted by the test phones would not interfere with, nor distort, data from the response pad or that processed by the electrode leads; determining whether electrode leads cause an increase or decrease in SAR; and examining the issue of experimenter interference. These tests enabled the conclusion that a positive finding from the large experimental trial would be due to the active exposure of the mobile phone, or in the case of a null finding, would not be due to insufficient or unreliable exposure. Applying the knowledge gained from these technical tests, the main study aimed to provide results of a definitive nature by employing a sample size of 120 sufficient statistical power to detect relatively subtle effects, and a stringent methodological design to account for past limitations. The main study also increased the scope of investigation beyond that achieved in previous research by including endpoints related to sensory processing (auditory and visual tasks), higher cognitive processing (cardsorting task), performance (reaction time and accuracy) and cortical activation (EEG alpha power). To increase this scope even further, within these tasks, the study used data from each scalp electrode and offered insights into the effect of laterality (ipsi- versus contralateral in relation to the exposure source), psychological arousal, perception of transmission, and between-subject factors such as age, gender, previous mobile phone use and hemisphere exposed (right versus left hemisphere exposure). The results of the main study suggested that acute exposure to GSM900 mobile phone significantly reduced levels of psychological arousal, particularly in relation to selfratings of Energy. Results also indicated that only minutes of active exposure can lead to enhanced alpha EEG activity during active exposure relative to sham exposure. Interestingly, this effect was found to be transient, decreasing below sham levels after ten minutes of active exposure and up until ten minutes after exposure cessation. These exposure-induced changes in EEG alpha power were here interpreted as representing an overall reduction in integrative brain function, possibly caused by the physiological response to neural interference or altered synaptic transmission. Acute exposure did not alter human brain activity in the form of the early sensory or later cognitive ERP responses during an auditory or visual task, or EEG synchronisation during a higher cognitive task. The findings also suggested that resultant behaviour, as indexed by RT and accuracy, is unaffected by exposure. Conversely, exploration into specific groups within the sample resulted in some interesting interactions, which raised the possibility that active mobile phone exposure may affect individuals differently as a function of age, gender and which hemisphere is exposed. Specifically, the auditory processing of older individuals was particularly vulnerable to the detrimental effects of mobile phone exposure compared to their younger counterparts. Results of the visual task suggested that the performance of females may also be particularly vulnerable to the detrimental effects of active exposure, compared to males. Overall, the present study has confirmed that there are mobile phone-related bioeffects at the low levels that mobile phones are permitted to operate at. Although various effects have been observed, there is no indication from the present results that cumulative effects or any health consequences exist as this was not the focus of the research. It is argued that future investigation into mobile phone-related bioeffects should apply more sophisticated methodologies to the investigation of acute exposure on EEG alpha power and higher cognitive functioning, as well as larger sample sizes and fewer carefully planned comparisons in order to detect small effects. Further investigation into exposure-induced effects on different groups according to age, gender and which hemisphere is exposed should also be a priority.