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Tytuł:
Levels of electromagnetic fields from rail vehicles in the context of formal requirements
Autorzy:
Miszkiewicz, Andrzej
Tchórzewski, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/215391.pdf
Data publikacji:
2020
Wydawca:
Instytut Kolejnictwa
Tematy:
electromagnetic fields
civil protection
measurements
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.
Źródło:
Problemy Kolejnictwa; 2020, 187; 109-116
0552-2145
2544-9451
Pojawia się w:
Problemy Kolejnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electromagnetic fields exposure assessment among workers at broadcast centers in Poland
Autorzy:
Politański, Piotr
Aniołczyk, Halina
Gadzicka, Elżbieta
Bortkiewicz, Alicja
Zmyślony, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2162494.pdf
Data publikacji:
2018-10-30
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
occupational exposure
television
electromagnetic fields
exposure assessment
radio
work safety in electromagnetic fields
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
Źródło:
Medycyna Pracy; 2018, 69, 5; 477-482
0465-5893
2353-1339
Pojawia się w:
Medycyna Pracy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of potential dangers of Mobile Telecommunication frequencies and modulations
Autorzy:
Bamisaye, A. J.
Powiązania:
https://bibliotekanauki.pl/articles/307594.pdf
Data publikacji:
2013
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
electromagnetic fields
frequency
health
mobile communication
modulation
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.
Źródło:
Journal of Telecommunications and Information Technology; 2013, 2; 30-34
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
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
Powiązania:
https://bibliotekanauki.pl/articles/2179019.pdf
Data publikacji:
2014-12-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
occupational exposure
measurements
electromagnetic fields
exposure pattern
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.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2014, 27, 6; 1043-1054
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The pattern of the electromagnetic field emitted by mobile phones in motor vehicle driving simulators
Autorzy:
Politański, Piotr
Bortkiewicz, Alicja
Zmyślony, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2179152.pdf
Data publikacji:
2013-06-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
electromagnetic fields
mobile phones
UMTS
traffic accidents
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.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2013, 26, 3; 471-476
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
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.
Powiązania:
https://bibliotekanauki.pl/articles/261628.pdf
Data publikacji:
2009
Wydawca:
Politechnika Wrocławska. Wydział Podstawowych Problemów Techniki. Katedra Inżynierii Biomedycznej
Tematy:
pola elektromagnetyczne
strefa ochronna
electromagnetic fields
protective zone
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.
Źródło:
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna; 2009, 15, 1; 44-48
1234-5563
Pojawia się w:
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
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
Powiązania:
https://bibliotekanauki.pl/articles/2180112.pdf
Data publikacji:
2012-03-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
base stations
electromagnetic fields
health effects
subjective symptoms
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.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2012, 25, 1; 31-40
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skutki biologiczne ekspozycji na pola elektromagnetyczne– badania eksperymentalne
Biological effects of exposure to electromagnetic fields – an experimental study
Autorzy:
Wiaderkiewicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/138025.pdf
Data publikacji:
2008
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
pola elektromagnetyczne
in vitro
in vivo
electromagnetic fields
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.
Źródło:
Podstawy i Metody Oceny Środowiska Pracy; 2008, 4 (58); 47-65
1231-868X
Pojawia się w:
Podstawy i Metody Oceny Środowiska Pracy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lorentz transformation of radiation 4-potential
Autorzy:
Comay, E.
Powiązania:
https://bibliotekanauki.pl/articles/1050861.pdf
Data publikacji:
2018-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
covariance
4-potential
electromagnetic radiation
electromagnetic fields
Lorentz invariants
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.
Źródło:
Acta Physica Polonica A; 2018, 133, 5; 1294-1298
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Letter to the Editor (July 26, 2017) concerning the paper “Impact of electromagnetic radiation emitted by monitors on changes in the cellular membrane structure and protective antioxidant effect of vitamin A – In vitro study”
Autorzy:
Mortazavi, Seyed M.
Powiązania:
https://bibliotekanauki.pl/articles/2159960.pdf
Data publikacji:
2017-12-21
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
electromagnetic fields
EMF
monitors
cell membrane
antioxidants
vitamin A
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2018, 31, 3; 371-372
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Plasma thyroid hormones and corticosterone levels in blood of chicken embryos and post hatch chickens exposed during incubation to 1800 MHz electromagnetic field
Autorzy:
Pawlak, Krzysztof
Sechman, Andrzej
Nieckarz, Zenon
Powiązania:
https://bibliotekanauki.pl/articles/2178802.pdf
Data publikacji:
2014-01-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
electromagnetic fields
mobile phone
thyroid hormone
corticosterone
chicken embryo
Opis:
Introduction: This study attempted to determine the effect of a 1800 MHz electromagnetic field (EMF) (only carrier frequency) on thyroxine (T₄), triiodothyronine (T₃) and corticosterone (CORT) concentrations in the blood plasma of chick embryos, and to investigate the effect of electromagnetic field (EMF) exposure during embryogenesis on the level of these hormones in birds that are ready for slaughter. Material and Methods: Throughout the incubation period, embryos from the experimental group were exposed to a 1800 MHz EMF with power density of 0.1 W/m², 10 times during 24 h for 4 min. Blood samples were collected to determine T₄, T₃ and CORT concentrations on the 12th (E12) and 18th (E18) day of incubation, from newly hatched chicks (D1) and from birds ready for slaughter (D42). Results: The experiment showed that T₄ and T₃ concentrations decreased markedly and CORT levels increased in the embryos and in the newly hatched chicks exposed to EMF during embryogenesis. However, no changes were found in the level of the analyzed hormones in the birds ready for slaughter. Differences in T₄ and T₃ plasma concentrations between the EMF-exposed group and the embryos incubated without additional EMF were the highest in the newly hatched chicks, which may be indicative of the cumulative effect of electromagnetic field on the hypothalamo-pituitary-thyroid axis (HPT). Discussion: The obtained results suggest that additional 1800 MHz radio frequency electromagnetic field inhibits function of HPT axis, however, it stimulates hypothalamo- pituitary-adrenal axis by inducing adrenal steroidogenic cells to synthesize corticosterone. Further investigations are needed to elucidate the mechanisms by which radio EMFs affect HPT and HPA axis function in the chicken embryos.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2014, 27, 1; 114-122
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The risk of subjective symptoms in mobile phone users in Poland – An epidemiological study
Autorzy:
Szyjkowska, Agata
Gadzicka, Elżbieta
Szymczak, Wiesław
Bortkiewicz, Alicja
Powiązania:
https://bibliotekanauki.pl/articles/2178839.pdf
Data publikacji:
2014-05-17
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
electromagnetic fields
feeling of warmth
headaches
cell phone
subjective complaints
Opis:
Objectives: To assess the type and incidence of subjective symptoms related to the use of mobile phones in Polish users. Material and Methods: The study was conducted in 2005 using a questionnaire survey. Although it has been quite a long time, up to now, no such data have been published for Poland. The questionnaire consisted of 53 questions concerning sex, age, education, general health, characteristics of a mobile phone (hand-held, loud-speaking unit) as well as the habits associated with its use (frequency and duration of calls, text messages, etc.) and complaints associated with using a mobile phone. Results: As many as 1800 questionnaires were sent. The response was obtained from 587 subjects aged 32.6±11.3 (48.9% women, 51.1% men); the age did not differ significantly between men and women. The subjects owned a cell phone for an average of 3 years. Majority of the respondents used the phone intensively, i.e. daily (74%) or almost daily (20%). Headaches were reported significantly more often by the people who talked frequently and long in comparison with other users (63.2% of the subjects, p = 0.0029), just like the symptoms of fatigue (45%, p = 0.013). Also, the feeling of warmth around the ear and directly to the auricle was reported significantly more frequently by the intensive mobile phone users, compared with other mobile phone users (47.3%, p = 0.00004 vs. 44.6%, p = 0.00063, respectively). Most symptoms appeared during or immediately after a call and disappeared within 2 h after the call. Continuous headache, persisting for longer than 6 h since the end of a call, was reported by 26% of the subjects. Conclusions: Our results show that the mobile phone users may experience subjective symptoms, the intensity of which depends on the intensity of use of mobile phones.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2014, 27, 2; 293-303
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biological risk assessment of high-voltage transmission lines on worker’s health of electric society
Autorzy:
Bidi, Manel
Powiązania:
https://bibliotekanauki.pl/articles/141717.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biological risk
electromagnetic fields
extremely low frequency
induced current
overhead lines
Opis:
A probable risk for different diseases has been reported due to exposure of peoples living in the vicinity of electrical substations and electrical workers. The aim of this paper is to examine and reduce the induced current density due to the power system field acting on human beings in the working environment, by using the spheroidal calculation model. The results obtained by means of computer programs developed by the author in the MATLAB environment are compared with the limit values given by the International Committee on Non-Ionizing Radiation Protection (ICNIRP) for demonstrating the degree of danger due to the induced current and have a certain guidance function for worker’s health to ensure their safety
Źródło:
Archives of Electrical Engineering; 2020, 69, 1; 57-68
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elektroniczne systemy sygnalizacji kradzieży jako źródła pól elektromagnetycznych
Autorzy:
Marzec, S.
Nowicka, J.
Powiązania:
https://bibliotekanauki.pl/articles/370948.pdf
Data publikacji:
2008
Wydawca:
Wyższa Szkoła Zarządzania Ochroną Pracy w Katowicach
Tematy:
pola elektromagnetyczne
elektroniczne systemy antykradzieżowe
electromagnetic fields
electronic anti theft systems
Opis:
W artykule omówiono elektroniczne systemy sygnalizacji kradzieży jako źródła pól elektromagnetycznych. Scharakteryzowano systemy antykradzieżowe radiowe RF i akustycznomagnetyczne AM jedno- i wieloantenowe oraz przedstawiono własne wyniki pomiarów natężenia pola emitowanego przez dwuantenowe akustycznomagnetyczne bramki typu ULTRA POST II, stosowane w hipermarketach. Wykazano, że w odległości do 10 cm od badanych bramek występuje pole elektromagnetyczne o natężeniu odpowiadającym pośredniej strefie ochronnej. Ponieważ w obszarze tym nie przebywają pracownicy, nie ma potrzeby oznaczać źródeł ani granic stref ochronnych. Natomiast wskazane jest zbadanie natężenia pola elektromagnetycznego innych bramek, zwłaszcza emitujących pole o częstotliwości powyżej 3 MHz, dla których dopuszczalne narażenie ludności i pracowników jest znacznie mniejsze niż na pola o mniejszej częstotliwości.
In this article the electronic anti theft systems as the electromagnetic fields sources were discussed. The RF radio and the mono antennas and multiple antennas AM magnetoacoustic anti theft systems were summarized and also the measurement own results of the field intensity beamed by two-antennas gates ULTRA POST II were presented. It was revealed that 10 cm from the examined gates the electromagnetic field is occurred, with the intensity corresponding the intermediate protective zone. In this area the workers stay away, so the sources or protective zones borders marking isn’t needful. However, the examination of the other gates electromagnetic field intensity is advisable, especially these beamed above 3 MHz frequency electromagnetic fields, from which the acceptable population and workers exposure is greatly slighter.
Źródło:
Zeszyty Naukowe Wyższej Szkoły Zarządzania Ochroną Pracy w Katowicach; 2008, 1(4); 57-66
1895-3794
2300-0376
Pojawia się w:
Zeszyty Naukowe Wyższej Szkoły Zarządzania Ochroną Pracy w Katowicach
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure recognition of conductive materials utilizing FE-algorithms of non-destructive eddy-current testing
Rozpoznawanie struktury materiałów przewodzących przy wykorzystaniu algorytmów defektoskopii wiroprądowej opartych na MES
Autorzy:
Gawrylczyk, K.
Kugler, M.
Powiązania:
https://bibliotekanauki.pl/articles/156974.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
elektromagnetyzm
metoda elementów skończonych
pola elektromagnetyczne
electromagnetism
finite element analysis
electromagnetic fields
Opis:
The paper deals with progress in electromagnetic methods used for structure evaluation of conducting materials. The term "electromagnetic methods" covers the following areas: magneto-inductive methods, magnetic leakage flux probe method, magnetometer principle and eddy-current methods. In 6948 the German visionary Friedrich Förster established his own company and developed highly sensitive measuring devices for magnetic fields at the Kaiser-Wilhelm-Institute. The methods and examples described in this paper relate only to eddy-current method, but the same idea may be applied for other methods, indeed. For the aim of inner structure recognition the sensitivity analysis with finite elements is proposed.
Praca dotyczy postępu w elektromagnetycznych metodach badania struktur przewodzących. Od roku 1948, gdy niemiecki wizjoner Friedrich Förster rozpoczął badania w Instytucie Cesarza Wilhelma w badaniach tych nastąpił wielki rozwój. Metody i przykłady opisane w niniejszej pracy odnoszą się jedynie do wiroprądowych badań materiałów, jednak przedstawiona idea może być łatwo przeniesiona do innych metod elektromagnetycznych. Opiera się ona na analizie układu pomiarowego metodą elementów skończonych, a następnie na przeprowadzeniu zadania odwrotnego umożliwiającego identyfikację struktury wewnętrznej materiału. Efektywne przeprowadzenie takiego zadania wymaga dostarczenia informacji o gradiencie funkcji celu, do czego wykorzystywana jest analiza wrażliwościowa wielkości pola elektromagnetycznego. Metody tej analizy, dobrze poznane i opisane w teorii obwodów elektrycznych, są dopiero rozwijane dla pól elektromagnetycznych. Zadania odwrotne prowadzą zwykle do źle uwarunkowanych, nadokreślonych układów równań. Uzyskane rozwiązanie jest często wynikiem kompromisu możliwej do uzyskania rozdzielczości w stosunku do użytych danych pomiarowych obciążonych błędami. Zastosowanie regularyzacji pozwala uzyskać zbieżność algorytmu nawet w takich przypadkach.
Źródło:
Pomiary Automatyka Kontrola; 2007, R. 53, nr 6, 6; 14-17
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 46

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