IEEE-USA E-Books

• Analysis of EMP Propagation in Protection Engineering

  In this paper, a body of revolution finite difference time domain (BOR-FDTD) is introduced. The propagation of the high power microwave (HPM) and ultra wide band (UWB) electromagnetic pulse in protection engineering is analyzed for the TE₀₁, TE₁₁ and TM₀₁ modes. Some numerical and experimental results showed good agreement, and valuable conclusions are obtained.

• Estimation of the EMP response of a system from its continuous wave measurement results

  Traditionally, the electromagnetic protection ability of a system, such as filters, shielding enclosures, etc., is measured in the frequency-domain and expressed as insertion loss or shielding effectiveness. When the time-domain characteristics of the system are required to evaluate their pulse response, time-domain tests need to be conducted. However, it may not be convenient to carried out time-domain tests because of the availability of test facilities. Theoretically, suppose the system works in a linear range, its pulse response can be estimated from frequency-domain measured data. We evaluated this concept by experiments. A digital filter model of the system under test is used to approximate the measured frequency response and then employed to calculate the output of the system under pulsed input. The estimated pulse responses are compared with measured ones. Results show that it is possible to estimate approximately the magnitude and shape of the time-domain response by this approach.

• shielding Effectiveness of Metal Door in Circular Tunnel to Non-unclear EMP

  In this paper, a body of revolution finite difference time domain (BOR-PDTD) is introduced. The shielding effectiveness of metal door in circular tunnel to non-nuclear electromagnetic pulse (HPM and UWB) in protective engineering is analyzed. The numerical results showed good agreement with those obtained from experiment, and some valuable conclusions are obtained.

• Experiments on the susceptibility of the direct digital control system to EMP in intelligent buildings

  Direct digital control (DDC) systems now play an important role in intelligent control of modern buildings. The susceptibility of these control systems to the pulsed electromagnetic environment is studied. A model of a DDC system consisting of computer, communication line and digital controller was tested in a HEMP simulator and a pulsed magnetic field simulator. We measured the interference thresholds of the computer and the DDC controller as well as the coupling of the outside field to the shielded twisted lines. The communication line was found to be the main path that causes interference in the DDC. Protection approaches, which can greatly reduce the sensitivity of the system to EMP interference, were also developed for the system.

• Application of MW-FDTD to simulate the electromagnetic pulse(EMP) propagation in tunnel

  To simulate the EMP propagation in large-scale and long-distances vaulted tunnel, an effective MW-FDTD method based on parallel computing was presented. The convolution PML (CPML) is adopted to truncate the computation domain, which reduces the reflection error greatly. The accuracy and the efficiency of the proposed method have been verified by comparing the results of the parallel FDTD algorithm with the proposed method.

• The definition of EMP shielding effectiveness

  In this paper the experimental results of the interference and damage effects of plane-wave EMP and pulsed magnetic field on microcomputer and microcomputer measuring and control apparatus are introduced. Then some important conclusions are obtained, and, on this basis, the author presents the definition of EMP shielding effectiveness.

• The modeling and experimental investigation on coupling of transmission line network with electromagnetic pulse (EMP)

  With the development of high power electromagnetic pulse (EMP) resources, intentional electromagnetic interference (IEMI) has become a practical threaten to power line network and SCADA system because of their sensitivity and vulnerability to EMP attack. In this paper, the transmission line models are built for two parallel power lines and several transmission line network models. The coupling of EMP (HEMP, square wave EMP) with transmission line network is simulated and the dependences of induced current and voltage are investigated. The results show that the proposed models of transmission line and network can predict the coupling process with EMP and the coupling mechanism can provide useful information for the protection, reliability of power line network.

• Effect of EMP on mice polydactylia and related genes expression (Gli3, Shh and Fgf4) during the development of mice limbs

  This paper observe mice polydactylia induced by EMP and related genes expressions (GliS5 Shh and Fgf4) during the development of mice limbs. Mature female mice were mated overnight with male mice (2:1). The morning on which a vaginal plug was found was designated as fetation-day-0. The pregnant mice were randomly divided into control group and EMP radiation group. Mice in the EMP radiation group were exposed to EMP from fetation-day-7 to fetation- day-10. The field intensity was 400 kVmiddotm-1 with 400 pulses. On the fetation-day-18, the embryos were taken out by cesarean section. The polydactylia were recorded. Morphological analysis of polydactylia was performed by using Alcian blue-Alizarin red staining method. The pregnant mice were randomly divided into negative control group, positive control group and EMP radiation group. Mice in the EMP radiation group were exposed to EMP from fetation-day-7 to fetation-day-10. The field intensity was 400 kVmiddotm-1 with 400 pulses. Mice in the positive control group were injected with 300 mgmiddotkg-1 of BrdU on the fetation-day-9 and fetation-day-10 days. On fetation-day-11, the embryos were taken out by cesarean section. The expressions of Gli3 Shh and Fgf4 were detected by Whole-mount in situ hybridization. This subject was supported by National Natural Science Fund (No. 60471032). Morphological analysis indicated that the polydactylia rate of the EMP radiation group was significantly higher than that of the control group (P<0.05). And it was also indicated that limb abnormality often occurred to the hindlimbs. In embryo limbs (fetation-day-11) of the EMP radiation group and the positive control group, the ectopic expression of Fgf4 was detected in AER; the overexpression and ectopic expression of Shh were detected in the ZPA; the decreased expression of Gli3 was detected in mesenchyme cells. The occurrence of polydactylia in mice increased after EMP radiation and it may have some relationship with the abnormal expressions of the above-mentioned genes

• Effects of EMP exposure on mice lymphocytes

  The bioeffects of EMP exposure on mice lymphocytes are observed. Mice were whole-body exposed to different field intensity of EMP (0, 50, 100, 200 and 400 kV/m) for 200 pulses. The effects of EMP exposure on mice lymphocytes proliferation were studied by 3H-thymidine ( 3H-TdR) incorporation. Cell cycle was evaluated by flow cytometry (FCM). The ultrastructure of mice lymphocytes was observed by transmission electron microscope (TEM). HPRT gene mutation of mice peripheral blood lymphocytes were investigated by lymphocyte cloning assay. The proliferation index of T lymphocytes increased after exposure to 100 kV/m and 200 kV/m EMP. The proliferation index of B lymphocytes were decreased after exposure to 400 kV/m EMP. EMP exposure led the ultrastructure alteration of mice lymphocytes and influenced the cell cycle progression of mice lymphocytes. HPRT gene mutant frequency of mice peripheral blood lymphocytes in 400 kV/m EMP exposure group is significantly increased. EMP exposure put some effects on the proliferation, cell cycle progression and ultrastructure of mice lymphocytes. Followed EMP exposure, HPRT gene mutant frequency were increased in a field intensity-dependent way

• Transient Characterization of Power Divider Response Illuminated by a High-Power EMP

  It is well known that intentional or unintentional electromagnetic interference can cause improper functionality of microwave circuits or systems, and in this paper, we examine transient responses of power dividers illuminated by a high-power EMP. The mathematical treatment is based on modified FDTD method. Numerical calculation is performed to show the EMP impact on the input-output responses of some power dividers which are often used in the integration of monolithic microwave integrated circuits.