scholarly journals ANALISIS INTENSITAS RADIASI MEDAN MAGNET MATAHARI

2021 ◽  
Vol 7 (1) ◽  
pp. 169
Author(s):  
Sudarti Sudarti ◽  
Sherly Nur Laili
Keyword(s):  
Magnetic Field ◽  
Solar Radiation ◽  
Radiation Intensity ◽  
Low Frequency ◽  
Wave Radiation ◽  
The Sun ◽  
Extremely Low Frequency ◽  
Field Radiation ◽  
C 32 ◽  
The Magnetic Field

ABSTRAKMedan magnet ELF (Extremely Low Frequency) merupakan spektrum gelombang elektromagnetik yang frekuensinya 0-300 Hz. Matahari sumber kehidupan yang memancarkan energinya ke bumi dalam bentuk radiasi gelombang elektromagnetik. Penelitian ini bertujuan untuk membandingkan intensitas radiasi medan magnet alamiah matahari didalam ruangan dan diluar ruangan. Jenis penelitian yang digunakan adalah penelitian eksperimen. Pengukuran intensitas radiasi medan magnet oleh matahari menggunakan alat Electromagnetic Field (EMF) Meter dan thermometer. Penelitian dilakukan mulai pukul 06.00 – 15.00 WIB dimana semakin siang temperatur medan magnet dan radiasi matahari semakin meningkat, kemudian suhu dan intensitas menurun seiring dengan terbenamnya matahari. Teknik analisa data yang digunakan menggunakan SPSS dengan metode interpretasi data. Hasil Penelitian menunjukkan data diluar ruangan memiliki hasil lebih tinggi dibandingkan dengan data hasil penelitian di dalam ruangan yakni rerata suhu didalam ruangan 29,5˚C, 31˚C, 32,36˚C,dan 31,7˚C sedangkan diluar ruangan 30,9˚C, 32,9˚C, 33,4˚C, 32˚C. Rerata medan magnet didalam ruangan sebesar 0,044, 0,224, 0,262, dan 0,326, sedangkan diluar ruangan sebesar 0,098, 0,324, 0,418, dan 0,398.  Data penelitian menunjukkan bahwa semakin tinggi intensitas radiasi matahari mengakibatkan temperatur bumi, dan medan magnet semakin tinggi. Kata kunci: intensitas;matahari; medan magnet;radiasi. ABSTRACTElf magnetic field (Extremely Low Frequency) is a spectrum of electromagnetic waves whose frequency is 0-300 Hz. Sun is a source of life that emits its energy to earth in the form of electromagnetic wave radiation. This study aims to compare the radiation intensity of natural magnetic fields by the sun indoors and outdoors. The type of research used is experimental research. Measurement of magnetic field radiation intensity by the sun using EMF Meter and thermometer. The research was conducted from 06.00 – 15.00 WIB where the more daylight the temperature of the magnetic field and solar radiation increases, then the temperature and intensity decreases with the sunset. Data analysis techniques used using SPSS with data interpretation methods. The results showed that outdoor data had higher results compared to the data of indoor research results, namely the average indoor temperature of 29.5°C, 31°C, 32.36°C, and 31.7°C while outdoors 30.9°C, 32.9°C, 33.4°C, 32°C. The average indoor magnetic field is 0.044, 0.224, 0.262, and 0.326, while outdoors is 0.098, 0.324, 0.418, and 0.398.  Research data shows that the higher the intensity of solar radiation results in the Earth's temperature, and the magnetic field gets higher. Keywords: intensity;sun; magnetic field;radiation.

Solar Radiation at 1200 MC/S., 600 MC/S., and 200 MC/S

1949 ◽  
Vol 2 (1) ◽  
pp. 48 ◽  
Author(s):  
FJ Lehany ◽  
DE Yabsley
Keyword(s):  
Magnetic Field ◽  
Body Temperature ◽  
Solar Radiation ◽  
Thermal Emission ◽  
Black Body ◽  
Sunspot Area ◽  
The Sun ◽  
Long Period ◽  
Period Variations ◽  
The Magnetic Field

Daily observations of solar radiation at frequencies of 1200 Mc/s., 600 Mc/s., and 200 Mc/s. taken between August 18 and November 30, 1947, are described. The characteristics of the radiation at 200 Mc/s. were in general agreement with those observed by earlier workers. At 600 Mc/s. and 1200 Mc/s., the received intensity was normally steady on any one day but underwent long-period variations over a range of about two to one. The radiation received when the sun was almost free of sunspots corresponded to an effective black-body temperature of 0.5 million �K. at 600 Mc/s. and 0.1 million �K. at 1200 Mc/s. As sunspots appeared, the temperature rose and showed marked oar- relation with sunspot area. It is considered that radiation at these frequencies is entirely thermal in origin and that the long-period variations are at least partly due to the influence of the magnetic field of sunspots on the mechanism of thermal emission from a magneto-ionic medium. On a few occasions, isolated disturbances were observed on 600 Mc/s. and 1200 Mc/s. some of which were associated with chromospheric flares and radio fade-outs. The difficulties arising in the calibration of the apparatus and the steps taken to overcome them are discussed in detail.

scholarly journals Self-Organizing Map Classification of the Extremely Low-Frequency Magnetic Field Produced by Typical Tablet Computers

2018 ◽  
Vol 18 (3) ◽  
pp. 94-99
Author(s):  
Darko Brodić ◽  
Alessia Amelio ◽  
Ivo R. Draganov
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Self Organizing Map ◽  
Tablet Computers ◽  
High Exposure ◽  
Extremely Low Frequency ◽  
Frequency Magnetic Field ◽  
The Magnetic Field ◽  
Self Organizing

Abstract In this paper, the extremely low frequency magnetic field produced by the tablet computers is explored. The measurement of the tablet computers’ magnetic field is performed by using a measuring geometry previously proposed for the laptop computers. The experiment is conducted on five Android tablet computers. The measured values of the magnetic field are compared to the widely accepted TCO safety standard. Then, the results are classified by the Self-Organizing Map method in order to create different levels of safety or danger concerning the magnetic field to which tablet computer users are exposed. Furthermore, a brief comparison of the obtained magnetic field levels with the ones from typical laptops is performed. At the end, a practical suggestion on how to avoid the high exposure to the low frequency magnetic field emitted by the tablet computers is given.

scholarly journals Analysis of the Extremely Low Frequency Magnetic Field Emission from Laptop Computers

2016 ◽  
Vol 23 (1) ◽  
pp. 143-154 ◽  
Author(s):  
Darko Brodić
Keyword(s):  
Magnetic Field ◽  
Field Emission ◽  
Close Contact ◽  
Low Frequency ◽  
Laptop Computers ◽  
Extremely Low Frequency ◽  
Frequency Magnetic Field ◽  
High Emission ◽  
The Magnetic Field ◽  
Specific Experiment

Abstract This study addresses the problem of magnetic field emission produced by the laptop computers. Although, the magnetic field is spread over the entire frequency spectrum, the most dangerous part of it to the laptop users is the frequency range from 50 to 500 Hz, commonly called the extremely low frequency magnetic field. In this frequency region the magnetic field is characterized by high peak values. To examine the influence of laptop’s magnetic field emission in the office, a specific experiment is proposed. It includes the measurement of the magnetic field at six laptop’s positions, which are in close contact to its user. The results obtained from ten different laptop computers show the extremely high emission at some positions, which are dependent on the power dissipation or bad ergonomics. Eventually, the experiment extracts these dangerous positions of magnetic field emission and suggests possible solutions.

scholarly journals Long-Term Monitoring of Extremely Low Frequency Magnetic Fields in Electric Vehicles

2019 ◽  
Vol 16 (19) ◽  
pp. 3765 ◽  
Author(s):  
Yang ◽  
Lu ◽  
Lin ◽  
Li ◽  
Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electric Vehicles ◽  
Low Frequency ◽  
Epidemiological Studies ◽  
Magnetic Flux Density ◽  
Extremely Low Frequency ◽  
Long Term Monitoring ◽  
The Magnetic Field ◽  
Term Monitoring

Extremely low frequency (ELF) magnetic field (MF) exposure in electric vehicles (EVs) has raised public concern for human health. There have been many studies evaluating magnetic field values in these vehicles. However, there has been no report on the temporal variation of the magnetic field in the cabin . This is the first study on the long-term monitoring of actual MFs in EVs. In the study, we measured the magnetic flux density (B) in three shared vehicles over a period of two years. The measurements were performed at the front and rear seats during acceleration and constant-speed driving modes. We found that the B amplitudes and the spectral components could be modified by replacing the components and the hubs, while regular checks or maintenance did not influence the B values in the vehicle. This observation highlights the necessity of regularly monitoring ELF MF in EVs, especially after major repairs or accidents, to protect car users from potentially excessive ELF MF exposure. These results should be considered in updates of the measurement standards. The ELF MF effect should also be taken into consideration in relevant epidemiological studies.

scholarly journals Range Detection of the Extremely Low-Frequency Magnetic Field Produced by Laptop’s AC Adapter

2017 ◽  
Vol 17 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Darko Brodić ◽  
Alessia Amelio
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Operating Conditions ◽  
Magnetic Field Measurement ◽  
Field Exposure ◽  
Heavy Load ◽  
Safety Standards ◽  
Extremely Low Frequency ◽  
Frequency Magnetic Field ◽  
The Magnetic Field

Abstract Human exposure to extremely low frequency magnetic field represents a risk to their health. This paper takes into consideration the level of an extremely low-frequency magnetic field between 30 and 300 Hz emitted by an AC laptop adapter. The experiment consists of testing 17 different AC adapters for laptops. During the testing, laptops are operated in a normal operating conditions as well as under heavy load. The magnetic field measurement is conducted in the area around the AC adapter. Obtained data is evaluated according to the critical level of the magnetic field proposed by safety standards. Furthermore, data is classified by a K-medians method in order to determine the critical levels of the magnetic field exposure in the nearby area of the AC adapter. Obtained classifications are evaluated according to safety standards, giving a critical analysis of magnetic field areas at risk. Due to emission of a very strong magnetic field in certain areas, a recommendation for safety use of the AC adapter is proposed.

scholarly journals Classification of the Extremely Low Frequency Magnetic Field Radiation Measurement from the Laptop Computers

2015 ◽  
Vol 15 (4) ◽  
pp. 202-209 ◽  
Author(s):  
Darko Brodić ◽  
Alessia Amelio
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Normal Operation ◽  
Low Frequencies ◽  
Laptop Computers ◽  
Safety Standards ◽  
Extremely Low Frequency ◽  
Operation Conditions ◽  
Frequency Magnetic Field ◽  
The Magnetic Field

Abstract The paper considers the level of the extremely low-frequency magnetic field, which is produced by laptop computers. The magnetic field, which is characterized by extremely low frequencies up to 300 Hz is measured due to its hazardous effects to the laptop user's health. The experiment consists of testing 13 different laptop computers in normal operation conditions. The measuring of the magnetic field is performed in the adjacent neighborhood of the laptop computers. The measured data are presented and then classified. The classification is performed by the K-Medians method in order to determine the critical positions of the laptop. At the end, the measured magnetic field values are compared with the critical values suggested by different safety standards. It is shown that some of the laptop computers emit a very strong magnetic field. Hence, they must be used with extreme caution.

Exposure of adults to extremely low frequency magnetic field in France: results of the EXPERS study

2019 ◽  
Vol 55 (1) ◽  
pp. 39-50 ◽  
Author(s):  
I. Magne ◽  
M. Souques ◽  
L. Courouve ◽  
A. Duburcq ◽  
E. Remy ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Personal Exposure ◽  
Epidemiological Studies ◽  
Field Exposure ◽  
Extremely Low Frequency ◽  
Measurement Protocol ◽  
Main Variable ◽  
Frequency Magnetic Field ◽  
The Magnetic Field

Assessing the exposure of adults to magnetic field is a central point in the context of epidemiological studies. The EXPERS study is the first study at national scale in Europe with measurements of personal exposure to extremely low frequency magnetic fields, involving 1046 French adults with 24 h personal measurements. The proportion of adults with a 24 h AM of ≥ 1 µT was 2.1% for all adults and 0.3% for adults for which no alarm clock was identified, as this requirement of the measurement protocol was sometimes not respected. The alarm clocks were the main variable linked to the adults’ exposure measurements. The vicinity of the home to a high voltage power line increased the magnetic field exposure. However, only 1.7% of the adults were living close to a 63 to 400 kV overhead line, and only one of them had a personal exposure ≥ 1 μT with an AM of 1.1 μT. The exposure of adults was also correlated with some characteristics of the home and its environment, and some durations of activities, such as the duration of work and the duration in rail transport. The distribution of adults’ personal exposure was significantly different from the distribution of exposure during sleep, and from the distribution of exposure assessed from measurements during sleep and work. This highlights the complexity of the exposure assessment in epidemiological studies.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

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