Temat: electromagnetic - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Lorentz transformation of radiation 4-potential
Autorzy:: Comay, E.
Tematy:: covariance
4-potential
electromagnetic radiation
electromagnetic fields
Lorentz invariants; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1050861.pdf Link otwiera się w nowym oknie
Opis:: The laws of Maxwellian electrodynamics are used in an analysis of the structure of the 4-potential of radiation fields. The paper examines multi-particle and single-particle effects of a radiating source. Causality of electromagnetic processes is an important element of the analysis. Covariance properties of the relevant variables are examined and the apparent non-covariance of the radiation 4-potential where A_{0}≡0 in all frames is explained. It turns out that the origin of this feature stems from the multi-charge properties of radiation. It is also shown how in every Lorentz frame one can use covariant properties of radiation fields and reconstruct an appropriate 4-potential.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Electromagnetic fields exposure assessment among workers at broadcast centers in Poland
Autorzy:: Politański, Piotr
Aniołczyk, Halina
Gadzicka, Elżbieta
Bortkiewicz, Alicja
Zmyślony, Marek
Tematy:: occupational exposure
television
electromagnetic fields
exposure assessment
radio
work safety in electromagnetic fields; Pokaż więcej
Wydawca:: Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Powiązania:: https://bibliotekanauki.pl/articles/2162494.pdf Link otwiera się w nowym oknie
Opis:: Background In the studies investigating the potential health effects of occupational exposure to electromagnetic fields (EMF), the key problem is the assessment of workers’ exposure. Electromagnetic fields exposure assessment requires determining maximum EMF levels, for the acute effect, and the dose absorbed, for the cumulative effect. A study was undertaken to determine EMF exposure in workers at broadcasting centers (BCs) in Poland. It was the first part of a comprehensive project on health effects of occupational exposure to EMF. Material and Methods The study was conducted in 4 selected BCs. Spot measurements of electric field strength (E), and the results of E measurements that were made in the past for occupational hygiene assessments, were used for determining workers’ exposure to electric field. The parameters considered were the maximum E value ($\text{E}_\text{max}$), the weighted average E value ($\text{E}_\text{avg}$) and the E lifetime dose ($\text{E}_\text{lifetime dose}$). Results In the group of workers examined, the E values did not exceed 16.7 V/m for Emax (the occupational exposure limit (OEL) for work shift in Poland is 20 V/m), 2.9 V/m for $\text{E}_\text{avg}$ and 1 500 000 (V/m)²×h for $\text{E}_\text{lifetime dose}$. Conclusions In view of the lack of dosimetry data, a retrospective assessment of BC workers’ exposure to very high frequency and ultra-high frequency EMF was conducted, which made it possible to estimate EMF lifetime dose for the workers. Since the EMF exposure levels at BCs did not exceed the admissible values, they can be considered safe to the workers’ health, according to the approach used for developing OELs for EMF exposure. Med Pr 2018;69(5):477–482
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Levels of electromagnetic fields from rail vehicles in the context of formal requirements
Autorzy:: Miszkiewicz, Andrzej
Tchórzewski, Krzysztof
Tematy:: electromagnetic fields
civil protection
measurements; Pokaż więcej
Wydawca:: Instytut Kolejnictwa
Powiązania:: https://bibliotekanauki.pl/articles/215391.pdf Link otwiera się w nowym oknie
Opis:: The article discusses the issue of electromagnetic field levels emitted from rail vehicles with regard to civil protection. The article presents the lack of legal solutions, limits and research methods in the railway industry in Poland. It also depicts the initial results of measurements from rail vehicles. Based on the findings, taking into consideration the measurement results and suppression of electromagnetic waves in free space, electromagnetic fields may reach substantial levels which can affect people’s health and life. The authors of the article conclude that the problem should not be ignored and requires further research, bearing in mind the progressing saturation of all rail vehicles with devices and electronic systems which will serve as sources of electromagnetic fields.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Numeryczne modelowanie pola elektromagnetycznego w uproszczonym modelu człowieka
Numerical modeling of electromagnetic fields in simplified model of human
Autorzy:: Podlodowska, J.
Tematy:: indukcja elektromagnetyczna
prądy wirowe
pole elektromagnetyczne
częstotliwość
modele numeryczne
electromagnetic induction
eddy currents
electromagnetic fields
frequency
numerical models; Pokaż więcej
Wydawca:: Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Powiązania:: https://bibliotekanauki.pl/articles/408436.pdf Link otwiera się w nowym oknie
Opis:: Artykuł zawiera opis badań, mających na celu przedstawienie numerycznego modelu prądów wirowych indukowanych w uproszczonym modelu człowieka przez zewnętrzne pole magnetyczne o częstotliwości 50 Hz. W pierwszej części pracy zawarto opis wpływu pola elektromagnetycznego na organizm człowieka. Następnie scharakteryzowano model wykorzystany do badania, a ostatnią część poświęcono metodom numerycznym, opisowi matematycznemu modelu oraz analizie numerycznej i porównaniu wyników z normami obowiązującymi w kraju i UE.
The article contains description of the research works, aimed to present a numerical model of eddy currents induced in a simplified model of a human under influence of 50 Hz external magnetic field. In the first part of the paper the influence of electromagnetic field on the human body has been described. Then, the model used for the research has been characterized. Finally, numerical methods, mathematical description of the model, as well as numerical analysis and comparison of the results referred to the Polish and EU standards have been included in the past part of the paper.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Evaluation of exposure to electromagnetic radiofrequency radiation in the indoor workplace accessible to the public by the use of frequency-selective exposimeters
Autorzy:: Gryz, Krzysztof
Karpowicz, Jolanta
Leszko, Wiesław
Zradziński, Patryk
Tematy:: occupational exposure
measurements
electromagnetic fields
exposure pattern; Pokaż więcej
Wydawca:: Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Powiązania:: https://bibliotekanauki.pl/articles/2179019.pdf Link otwiera się w nowym oknie
Opis:: Objectives: The aim of the study was to identify and assess electromagnetic radiofrequency radiation (EMRR) exposure in a workplace located in a publicly accessible environment, and represented by offices (where exposure is caused by various transmitters of local fixed indoor and outdoor wireless communication systems). Material and Methods: The investigations were performed in 45 buildings (in urban and rural areas in various regions of Poland), using frequency-selective electric field strength (E-field) exposimeters sensitive to the EMRR with a frequency range of 88–2500 MHz, split into 12 subbands corresponding to the operating frequencies of typical EMRR sources. The variability of the E-field was analyzed for each frequency range and the total level of exposure by statistical parameters of recorded exposimetric profiles: minimum, maximum, median values and 25–75th – percentiles. Results: The main sources of exposure to EMRR are mobile phone base transceiver stations (BTS) and radio-television transmitters (RTV). The frequency composition in a particular office depends on the building’s location. The E-field recorded in buildings in urban and rural areas from the outdoor BTS did not exceed respectively: medians – 0.19 and 0.05 V/m, 75th percentiles – 0.25 and 0.09 V/m. In buildings equipped with the indoor BTS antennas the E-field did not exceed: medians – 1 V/m, 75th percentiles – 1.8 V/m. Whereas in urban and rural areas, the median and 75th percentile values of the E-field recorded in buildings located near the RTV (within 1 km) did not exceed: 1.5 and 3.8 V/m or 0.4 and 0.8 V/m, for radio FM band or for TV bands, respectively. Conclusions: Investigations confirmed the practical applicability of the exposimetric measurements technique for evaluating parameters of worker’s exposure in both frequency- and time-domain. The presented results show EMRR exposure of workers or general public in locations comparable to offices to be well below international limits.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: The pattern of the electromagnetic field emitted by mobile phones in motor vehicle driving simulators
Autorzy:: Politański, Piotr
Bortkiewicz, Alicja
Zmyślony, Marek
Tematy:: electromagnetic fields
mobile phones
UMTS
traffic accidents; Pokaż więcej
Wydawca:: Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Powiązania:: https://bibliotekanauki.pl/articles/2179152.pdf Link otwiera się w nowym oknie
Opis:: Introduction: The paper reports the results of the determinations of UMTS EMF distributions in the driver's cab of motor vehicle simulators. The results will serve as the basis for future research on the influence of EMF emitted by mobile phones on driver physiology. Materials and Methods: Two motor vehicle driving simulators were monitored, while an EMF source was placed at the driver's head or on the dashboard of the motor vehicle driving simulator. For every applied configuration, the maximal electric field strength was measured, as were the values at 16 points corresponding to chosen locations on a driver's or passenger's body. Results: When the power was set for the maximum (49 mW), a value of 27 V/m was measured in the vicinity of the driver's head when the phone was close to the head. With the same power, when the phone was placed on the dashboard, the measured maximum was 15.2 V/m in the vicinity of the driver's foot. Similar results were obtained for the passenger. Significant perturbations in EMF distribution and an increase in electric field strength values in the motor vehicle driving simulator were also observed in comparison to free space measurements, and the electric field strength was up to 3 times higher inside the simulator. Conclusions: This study can act as the basis of future studies concerning the influence of the EMF emitted by mobile phones on the physiology of the driver. Additionally, the authors postulate that it is advisable to keep mobile phones at a distance from the head, i.e. use, whenever possible, hands-free kits to reduce EMF exposure, both for drivers and passengers.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Evaluation of potential dangers of Mobile Telecommunication frequencies and modulations
Autorzy:: Bamisaye, A. J.
Tematy:: electromagnetic fields
frequency
health
mobile communication
modulation; Pokaż więcej
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/307594.pdf Link otwiera się w nowym oknie
Opis:: Mobile Telecommunication is one of the fastest growing technologies in the world. The effects of its high frequencies and complex modulations to the exposed population are considered in this paper. Experimental studies examining a variety of effects on all levels of the organism, ranging from effects on single cells to effects which manifest themselves as reactions of the entire body, there have been a number of epidemiological studies in order to establish the possible causal correlations between higher exposures to HF EMFs. Recommendations on the reduction of the effects of EMFs of Mobile Telecommunication on humans was presented.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Subjective complaints of people living near mobile phone base stations in Poland
Autorzy:: Bortkiewicz, Alicja
Gadzicka, Elżbieta
Szyjkowska, Agata
Politański, Piotr
Mamrot, Paweł
Szymczak, Wiesław
Zmyślony, Marek
Tematy:: base stations
electromagnetic fields
health effects
subjective symptoms; Pokaż więcej
Wydawca:: Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Powiązania:: https://bibliotekanauki.pl/articles/2180112.pdf Link otwiera się w nowym oknie
Opis:: Objectives: The aim of our study was to assess the health conditions and subjective symptoms of the inhabitants living in the base stations vicinity and to analyse the relationship between the complaints and level of exposure to electromagnetic fields (EMF). Materials and Methods: Our study was performed in housing estates located in five regions of Łódź. The electric field measurements were performed in the buildings located closest to the azimuth of the antennas. Respondents were selected by trained interviewers using an uniform procedure. The number of the households to be examined was set at a minimum of 420. The questionnaire contained: demographic data, occupational and environmental exposure to EMF, health condition, subjective complaints. Results were adjusted for confounders (age, gender, EMF at the workplace and EMF emitted by household equipment) using multiple regression model. Results: 181 men and 319 women from 500 households were examined. Electric field above 0.8 V/m was recorded in 12% of flats. There was no significant correlation between electric field strength and the distance of examined flats from the base stations. To make possible comparison with relevant literature, we analysed also the frequency of the reported symptoms vs. the distance. Headache was declared by 57% people, most frequently (36.4%) living 100–150 m away from the base station compared to people living at longer distances (p = 0.013). 24.4% subjects, mostly living at a distance above 150 m, declared impaired memory. Difference was statistically significant in comparison with people living at other distances (p = 0.004). Conclusions: The explanation why we did not find any correlation between the electric field strength and frequency of subjective symptoms but found a correlation between subjective symptoms and distance from base station needs further studies. Maybe new metrics of exposure assessment should be adopted for this purpose.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Skutki biologiczne ekspozycji na pola elektromagnetyczne– badania eksperymentalne
Biological effects of exposure to electromagnetic fields – an experimental study
Autorzy:: Wiaderkiewicz, R.
Tematy:: pola elektromagnetyczne
in vitro
in vivo
electromagnetic fields; Pokaż więcej
Wydawca:: Centralny Instytut Ochrony Pracy
Powiązania:: https://bibliotekanauki.pl/articles/138025.pdf Link otwiera się w nowym oknie
Opis:: Prezentowana praca jest przeglądem badań eksperymentalnych nad wpływem pól elektromagnetycznych na procesy biologiczne przebiegające w organizmach żywych. Przedstawiono metody stosowane do oceny oddziaływania pól elektromagnetycznych na poziomie komórkowym oraz dokonano analizy otrzymanych za ich pomocą wyników.
The paper is a review of experimental studies on the effects of electromagnetic fields on biological processes in living organisms. It presents the methods used and analyses the results obtained with different experimental approaches.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Pola elektromagnetyczne w otoczeniu urządzeń fizykoterapeutycznych - aplikatory do terapii zmiennym polem magnetycznym
Electromagnetic fields in the vicinity of physicotherapeutic devices - applicators for time-varying magnetic field therapy
Autorzy:: Karpowicz, J.
Gryz, K.
Zradziński, P.
Tematy:: pola elektromagnetyczne
strefa ochronna
electromagnetic fields
protective zone; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Wydział Podstawowych Problemów Techniki. Katedra Inżynierii Biomedycznej
Powiązania:: https://bibliotekanauki.pl/articles/261628.pdf Link otwiera się w nowym oknie
Opis:: W artykule scharakteryzowano ekspozycję na zmienne pola magnetyczne wytwarzane przez urządzenia do magnetoterapii oraz ocenę oddziaływania tych pól na otoczenie. Na podstawie badań wykonanych przy ponad 60 aplikatorach do terapii polem magnetycznym ustalono, że pola stref ochronnych ekspozycji zawodowej oraz pola, w których mogą powstać zakłócenia pracy implantów medycznych, występują w odległości do 40-70 cm od środka różnych aplikatorów szpulowych o średnicy od 20 cm do 60 cm. Pola, w których mogą powstać zakłócenia urządzeń elektronicznych, występują w odległości do 200-300 cm od aplikatorów szpulowych. Zasięgi oddziaływania pól wytwarzanych przez innego typu aplikatory są wielokrotnie mniejsze.
The exposure to time-varying magnetic field emitted by devices for magnetic field therapy and evaluation of their influence on the environment, are characterized. Examina-tion of magnetic fields emitted by over 60 applicators shown that magnetic fields of the level exceeding generał public permissible exposure or exposure permissible for users of medical electronic implants can be found in the distance up to 40-70 cm from the centrę of various reel applicators of diameter of 20-60 cm. Magnetic fields, by which electronic devices can be affected by the field are present in a distance up to 200-300 cm from the reel applicators. Other types of applicators emit fields of lower level.
Dostawca treści:: Biblioteka Nauki

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