Features of generation and propagation of the extremely low frequency waves excited in the ionosphere under the powerful HF radioemission influence

The experimental results of the extremely low frequency emission characteristics excited in the outer ionosphere under the ionospheric plasma heating by high-latitude EISCAT facility are presented. The experiments have been conducted in the period of 20062010 yr. using two main schemes of extremely low frequency generation including the impact of the heating facility amplitude modulated emission and two unmodulated pump waves with the frequency detuning. In-situ measurements of the plasma wave disturbances were performed at the outer ionosphere heights using on-board equipment of DEMETER microsatellite. In work the spatial, amplitude and spectral characteristics of the generated extremely low frequency emissions are determined. It is shown that the characteristic size of the extremely low frequency emission is about 400600 km along the trajectory of the DEMETER microsatellite. The registration area spatial position is determined by both the applied generation scheme and the background plasma density distribution. The extremely low frequency emission electric field strength at the Earths outer ionosphere heights is 50330 V/m.

PENGARUH PAPARAN MEDAN MAGNET EXTREMELY LOW FREQUENCY (ELF) TERHADAP pH ROTI TAWAR

ABSTRAKRoti tawar adalah sumber karbohidrat memiliki umur simpan yang sangat pendek yakni empat sampai enam hari terhitung dari proses masa produksi. Penelitian ini bertujuan menyelidiki pengaruh paparan medan magnet Extremely Low Frequency (ELF) intensitas 500 µT dan 700 µT selama 60, 90, dan 120 menit terhadap pH roti tawar. Jenis penelitian yang digunakan yaitu eksperimen dengan desain penelitian Rancang Acak Lengkap (RAL). Ada dua kelompok dalam penelitian ini, yakni kelompok kontrol dan kelompok eksperimen dimana kelompok kontrol yang tidak dipapari medan magnet dan kelompok eksperimen diberi paparan medan magnet. Sampel yang digunakan dalam penelitian ini adalah roti tawar sari roti kupas sebanyak 126 sisir dimana kelompok kontrol sebanyak 18 sisir roti tawar dan kelompok eskperimen sebanyak 108 sisir roti tawar yang dibagi menjadi enam kelompok yang diberi perlakukan berupa paparan medan magnet ELF dengan intensitas 500 µT dan 700 µT selama 60, 90 dan 120 menit. Teknik analisis data dilakukan menggunakan SPSS 22 dengan uji Kruskal-Wallis. Berdasarkan hasil penelitian yang diperoleh paparan medan magnet ELF berpengaruh terhadap perubahan pH pada roti tawar. Dengan memaparkan medan magnet intensitas 500 µT lama paparan 60 menit dan 700 µT lama paparan 60 menit dapat menghambat penurunan pH roti tawar. Kata kunci: Medan Magnet ELF; Roti Tawar; pH. ABSTRACTBread is a source of carbohydrates that has a very short shelf life of four to six days from the production process. This study aims to examine the effect of exposure to an Extremely Low Frequency (ELF) magnetic field with an intensity of 500 µT and 700 µT for 60, 90, and 120 minutes on the pH of white bread. This research uses an experimental research type with the research design used is Completely Randomized Design (CRD). There were two groups in this study, namely the control group and the experimental group where the control group was not exposed to a magnetic field and the experimental group was exposed to a magnetic field. The samples used in this study were 126 combs of peeled white bread, where the control group consisted of 18 white bread combs and the experimental group consisted of 108 white bread combs which were divided into six groups which were treated in the form of exposure to the ELF magnetic field with an intensity of 500 µT and 700 µT for 60, 90 and 120 minutes. The data analysis technique was carried out using SPSS 22 with the Kruskal-Wallis test. The results of the study stated that exposure to the ELF magnetic field had an effect on changes in pH in white bread as shown by a graphic diagram. Exposure to a magnetic field intensity of 500 µT with an exposure time of 60 minutes and 700 µT with an exposure duration of 60 minutes can inhibit the decrease in the pH of white bread. Keywords: Magnetic Field; White Bread; pH.

Radiation and public health

The electromagnetic spectrum encompasses frequencies that range from above approximately 1020 hertz (Hz) for ionizing radiation at the high end of the spectrum to static fields and power frequencies of 50–60 Hz at the low end. In order of decreasing frequency, the spectrum comprises gamma-rays, X-rays, ultraviolet radiation, visible light, infrared radiation, microwaves, radio waves and extremely low frequency electric and magnetic fields (ELF EMF). This chapter reviews sources and health effects of human exposure to radiation within the electromagnetic spectrum, and for ionizing radiation exposure to subatomic particles, as well as reviewing policies for limiting human exposure where appropriate.

Comparing the Impact of Long-Term Exposure to Extremely Low-Frequency Electromagnetic Fields With Diverse Values on Anxiety, Memory, Learning, And Β-Amyloid Deposition In Adult Rats

Background: Extremely low-frequency electromagnetic fields (ELF-EMFs) have gathered significant consideration for their possible pathogenicity. However, their effects on nervous system functions were not fully clarified. In this study, our aim was to assay the effect of ELF-EMFs with different intensity on memory, anxiety, antioxidant activity, beta amyloid (Aβ) deposition and microglia population in rats. Materials and Methods: Fifty male adult rats were randomly separated into 5 groups; four groups exposed to a flux density of 1, 100, 500 and 2000 microtesla (µT), 50 Hertz (Hz) frequency for 1h/day for 2 months and one group as a control group. The control group were without ELF-EMF stimulation. After 8 weeks, passive avoidance and elevated plus maze (EPM) tests was performed to assess memory formation and anxiety-like behavior, respectively. Total free thiol groups and the index of lipid peroxidation were assessed. Also, for detection of β-Amyloid deposition and stained microglia in the brain, anti-β-amyloid and anti-Iba1 antibodies were used. Results: In the ELF-EMF exposure groups, the step-through latency was significantly greater in the retention test (100,500, and 2000 µT) than in the control group (P<0.05). Also, the percentage of the entries into the open arms in ELF-EMF exposure groups (especially 2000 µT) decreased than control group (P <0.05). No β-Amyloid depositions were detected in the hippocampus of different groups. An increase in microglia numbers in the 100, 500 and 2000 µT groups was observed in compare to the control and 1 µT group. Conclusion: Exposure to ELF-EMF had an anxiogenic effect on rats and promoted memory and also induced oxidative stress. No β-Amyloid depositions were detected in the brain. Also, positive effect of ELF-EMF was observed on population of microglia population in the brain.

Behavior of Microorganisms from Wastewater Treatments in Extremely Low-Frequency Electric Field

The paper presents the research results regarding the metabolism of microorganisms from domestic wastewater treatment-activated sludge. The research approached this issue by dielectric spectroscopy measurements, chemical analyses, and specific microbiological techniques. In addition, the influence of extremely low-frequency (ELF) electric fields (1÷500 Hz) on microbial metabolism was studied. Four representative frequencies have been identified: 49.9, 99.9, 130.8, and 150.4 Hz using dielectric spectroscopy applied to the investigated samples. Also, dielectric loss and conductivity evolutions showed significant discontinuities, indicating oscillation/resonance phenomena in the investigated biomass, unlike the sterilized sludge samples (obtained either by boiling or electrically, applying a voltage that creates a 100 V/m electric field strength on the sample), which did not show discontinuities; instead, the values of tgδ and σ were approx. 5-6 times larger. Chemical and microbiological tests have shown that the metabolism, growth, and multiplication of microorganisms in activated sludge are significantly increased after exposure to 4-6 V/m electric field strength of 50 Hz. The research may continue by developing equipment and a bioelectrotechnological process to significantly increase the efficiency of wastewater treatment plants.