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Electric-Field Strength
Published in John G. Webster, Halit Eren, Measurement, Instrumentation, and Sensors Handbook, 2017
An ac electric-field strength meter [9] includes two essential parts: (1) an antenna and (2) a detector (receiver). Other possible features are a transmission line or optical link, frequency-selective circuits, amplifying and attenuating circuits, an indicating device, and a nonconducting handle. The antenna characteristics can be calculated for simple geometries or determined by calibration. For example, linear antennas are often characterized by their effective length Leff [10], which determines the open-circuit voltage Voc induced at the antenna terminals: Voc=LeffEinc
Electrostatic devices related to pneumatic conveying of powders. A short literature review
Published in Particulate Science and Technology, 2021
Adoum Traoré Ndama, Elysée Obame Ndong, Hans Essone Obame, Eloi Jean Jacques Blampain
The device is essentially composed of the transport pipe which is connected to Faraday cage, the fan to convoy powder by air velocity, hopper to feed in powder in discontinuous operation (Figure 11) or dosing system in continuous operation (Figure 12). Moreover, the measures were carried out by three measuring devices. A Coulometer (JCI 178, Chilworth) connected to the Faraday cage, a flow meter (EE75 ModellB, E + E Elektronik), to measure the conveying air velocity and an electric field strength meter (PFM-711A, PROSTAT) which is positioned on the plastic pipe in order to detect the potential of pipe. Note that the measurements for the different sections were carried out only in the continuous operating mode.
Role of NF-κB activation in mouse bone marrow stromal cells exposed to 900 MHz radiofrequency fields (RF)
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Lin Zong, Zhen Gao, Wen Xie, Jian Tong, Yi Cao
The exposure system was described in detail earlier (Cao et al. 2010). Briefly, it consists of GTEM chamber (Giga-hertz Transverse Electro-Magnetic chamber, 5.67 m length, 2.83 m width and 2.07 m height), a signal generator (SN2130J6030, PMM, Cisano sul Neva, Italy) and a power amplifier (SN1020, HD Communication, Ronkonkoma, NY). The continuous wave 900 MHz RF signal was generated, amplified and fed into the GTEM chamber through an antenna (Southeast University, Nanjing, Jiangsu, China). The RF field within the GTEM was probed using a field strength meter (PMM, Cisano sul Neva, Italy) to determine the precise position which provided the required 120 μW/cm2 power intensity. The power was monitored continuously and recorded every 5 min in a computer controlled data logging system which indicated 12.178 ± 0.003 μW/cm2 during the 4-hr RF exposure. The GTEM was installed in a room which maintained 37°C similar to cells maintenance during RF exposure. Approximately 5 × 105/ml cells in 6 ml medium were placed in several separate petri dishes on a non-conductive table in GTEM at the precise location where the required 120 μW/cm2 power intensity was measured. At the input power intensity of 120 μW/cm2 and the direction of propagation of the incident field parallel to the plane of the medium, the peak and average specific absorption rates (SARs) estimated were 4.1 × 10−4 and 2.5 × 10−4 W/kg, respectively (Jin et al. 2012). The same GTEM chamber, without RF transmission, was used for control cells. The exposures were 4 hr/day for 5 consecutive days. The culture medium was changed once during the 5 days. Immediately after different exposures, all cells were kept in the incubator. Separate aliquots of cells were collected at 30 min, 2 and 24 hr post-exposures. The experiment was repeated three times.
Role of NF-κB activation in mouse bone marrow stromal cells exposed to 900-MHz radiofrequency fields (RF)
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Lin Zong, Zhen Gao, Wen Xie, Jian Tong, Yi Cao
The exposure system was described in detail earlier (Cao et al. 2010). Briefly, it consists of GTEM chamber (Giga-hertz Transverse Electro-Magnetic chamber, 5.67 m length, 2.83 m width, and 2.07 m height), a signal generator (SN2130J6030, PMM, Cisano sul Neva, Italy), and a power amplifier (SN1020, HD Communication, Ronkonkoma, NY). The continuous-wave 900-MHz RF signal was generated, amplified, and fed into the GTEM chamber through an antenna (Southeast University, Nanjing, Jiangsu, China). The RF field within the GTEM was probed using a field strength meter (PMM, Cisano sul Neva, Italy) to determine the precise position which provided the required 120 μW/cm2 power intensity. The power was monitored continuously and recorded every 5 min in a computer-controlled data logging system which indicated 12.178 ± 0.003 μW/cm2 during the 4-hr RF exposure. The GTEM was installed in a room which maintained 37°C similar to cells maintained during RF exposure. Approximately 5 × 105/ml cells in 6 ml medium were placed in several separate petri dishes on a non-conductive table in GTEM at the precise location where the required 120 μW/cm2 power intensity was measured. At the input power intensity of 120 μW/cm2 and the direction of propagation of the incident field parallel to the plane of the medium, the peak and average specific absorption rates (SARs) estimated were 4.1 × 10−4 and 2.5 × 10−4 W/kg, respectively (Jin et al. 2012). The same GTEM chamber, without RF transmission, was used for control cells. The exposures were 4 hr/day for 5 consecutive days. The culture medium was changed once during the 5 days. Immediately after different exposures, all cells were kept in the incubator. Separate aliquots of cells were collected at 30 min, 2 hr, and 24 hr postexposures. The experiment was repeated three times.