Effect of power cable insulator for power line communication

This paper describes a method for calculation of the effective relative dielectric constant εs of VVF cable. For power line communications (PLC), VVF cables in homes are used as 2‐ to 30‐MHz high‐frequency transmission media. As they are not designed and installed for such transmission media, there are many branches and impedance mismatch points that cause PLC signal reflections and standing waves. In order to estimate such standing wave generation and estimate undesirable PLC signal radio wave leakage, the length of the cable and the relative dielectric constant εs are important. However, the insulator of VVF cable is thin and not symmetric, so that it is not easy to calculate effective εs analytically. In this paper, the effective εs is calculated numerically using the PC software EXCEL by drawing the electrical fluxes and analyzing the effect of the insulator for each flux. The calculation result for VVF cable considering the limited insulator area around the conductors shows that the effective εs is about 13% less and the transmission speed is 7% faster than when the insulator occupies the full space around the cable. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(4): 24–31, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20862     

An estimation method of available transfer capabilities from viewpoint of power system transient stability under deregulated environment

To conduct electric power transactions effectively and to operate a power system efficiently while maintaining reliability under the deregulated environment, it is required that ATC (Available Transfer Capability) be calculated at high speed and with reasonable precision. In order to address this issue, in this paper, an Artificial Neural Network‐based estimation method for evaluating Maximum Transmission Capability (MTC), which is a key step but also a highly time consuming process in ATC, is proposed. It is confirmed through simulation studies that the proposed method is capable of estimating MTC (ATC) with high speed and sufficient precision. Furthermore, the authors examined the reduction of calculation time at learning by using the transient stability index. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(1): 66–73, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20781     

Exchange Flow Characteristics in a Tokamak Vacuum Vessel of Fusion Reactor Under the Loss-of-Vacuum Conditions

When a Tokamak vacuum vessel of fusion reactor is broken, buoyancy-driven exchange flows will take place through breaches after the inside pressure of the vacuum vessel (VV) becomes equal to the outside pressure. The exchange flow may bring a mixture of activated dusts and tritium from the inside of the VV to the outside through the breaches. Moreover, the exchange flow may remove decay heat from the plasma-facing components. A preliminary LOVA (Loss Of VAcuum event) apparatus was constructed to investigate quantitative heat transfer characteristics of the exchange flows through the breaches under the LOVA conditions. The results of this study, the relationship between Froude numbers and breach locations in the VV was determined and empirical correlations for the average Froude numbers were derived.     

Requirement of IL-4 and liver NK1+ T cells for concanavalin A-induced hepatic injury in mice

Con A-induced hepatic injury of mice accompanied by elevated transaminase was inhibited after in vivo depletion of liver NK cells and NK1+ T cells with intermediate TCR by anti-NK1 Ab or anti-IL-2Rbeta Ab. However, depletion of liver NK cells alone by anti-asialo-GM1 Ab did not inhibit hepatic injury. Although depletion of NK1+ T cells inhibited Con A-induced IL-2R expression of CD4+ high TCR (TCRhigh) cells and IL-4 mRNA expression of hepatic mononuclear cells, exogenous IL-4 engendered Con A-induced hepatic injury and endowed the expression of IL-2R of CD4+ TCRhigh cells. It was also found that in vivo treatment with anti-IL-4 Ab before Con A administration inhibited Con A-induced hepatic injury. In addition, although Con A did not induce hepatic injury in MHC class I-deficient mice, exogenous IL-4 again engendered severe hepatic injury in these mice. Further, while serum TNF-alpha levels induced by Con A were greatly decreased in NK1+ T cell-depleted mice and class I-deficient mice, TNF-alpha levels were recovered by exogenous IL-4. These findings reveal that although CD4+ TCRhigh cells in the liver and their production of TNF-alpha are the direct effectors of Con A-induced hepatic injury, liver NK1+ T cells also play an important role in this hepatitis model. Con A hepatitis may serve as an experimental model for human autoimmune hepatitis.     

Development of Safety Assessment Method for Plasma Anomaly Events in Fusion Reactors

The objective of the study is to provide a safety assessment method for plasma transients including thermal response of in-vessel components. We developed a plasma physics model for safety analysis which has been implemented in a safety analysis code (SAFALY). The SAFALY code consists of a 0-D plasma dynamics model and a 1-D thermal behavior model of in-vessel components in the thickness direction. The code can treat hydraulic accidents using the results from a hydraulic code and analyze a passive plasma shutdown due to the impurity release from the wall. The overpower events in International Thermonuclear Experimental Reactor (ITER) were investigated, when the fueling rate and confinement improvement changes. The results show no significant damage to the confinement boundary of ITER is expected, as long as the cooling system works normally.     

Development of a high resolution beta camera

We have developed and tested a high resolution beta camera. The beta camera consists of thin CaF2(Eu) scintillator, tapered fiber optics plate, position sensitive photomultiplier tube (PSPMT). The output of the PSPMT is fed to position calculation circuit and accumulated in the memory. The data in the memory is fed to personal computer for display and analysis. We have developed two types of beta cameras. One is 20 mm diameter field of view (FOV) camera, and the other is 10 mm diameter camera. Intrinsic spatial resolutions were 0.8 mm FWHM and 0.5 mm FWHM for 20 mm and 10 mm FOV camera, respectively. We confirmed that developed beta cameras may overcome the limitation of the resolution of the PET camera.     

Energy level alignment at organic/metal interfaces studied by UVphotoemission: breakdown of traditional assumption of a common vacuumlevel at the interface

Electronic structures of model interfaces of organic electroluminescent (EL) devices and porphyrin/metal interfaces were investigated by UV photoemission spectroscopy (UPS). At all the measured interfaces, shift of the vacuum level was observed, showing the formation of an interfacial electric dipole layer. For Alq₃ (tris(8-hydroxyquinolino) aluminum), TPD (N,N'-diphenyl-N,N'-(3-methylphenyl)-1,1-biphenyl-4,4'-diamine), and DP-NTCI (N,N'-diphenyl-1,4,5,8-naphthyltetracarboxylimide)/metal interfaces, interfacial energy diagrams determined by UPS correspond well with the actually observed carrier-injecting character at the interfaces. For ZnTPP (15,10,15,20-zinc-tetraphenylporphyrin), H₂ TPP (5,10,15,20-tetraphenylporphyrin), and H₂T(4-Py)P (5,10,15,20-tetra(4-pyridyl) porphyrin)/metal interfaces, the shifts of the vacuum level as well as the energies of the levels in porphyrins could be expressed as a linear function of work function of the metal substrate. The slope of the linear function depended on the compound. These findings are in contrast to the traditional assumption of common vacuum level at the interfaces, For ZnTPP/metal interfaces, sample exposure to oxygen induced energy level shift in close relation with the change of the substrate work function at oxygen exposure. The present results have clearly demonstrated that direct observation of the interfacial electronic structure by microscopic method such as UPS is necessary for understanding the organic electronic devices such as EL devices and organic solar cells     

Positive end-expiratory pressure facilitates washout of nitrous oxide in patients with obstructive pulmonary disease

The binding of native and reactive oxygen species-modified DNA (ROS-DNA) to circulating antibodies in the serum of patients with various types of cancer has been investigated by competition enzyme-linked immunosorbent assay. Fifteen sera of 35 showed reactivity with native and/or ROS-DNA. Eleven of these showed higher binding to ROS-DNA (36-64% inhibition), whereas 1 showed higher reactivity with native DNA (nDNA) (42% inhibition). Three sera reacted with both native and ROS-DNA almost equally. Oxidative lesions in human genomic DNA were immunochemically detected using an anti-ROS-DNA monoclonal antibody (MAb) probe. Two of 3 DNA isolates from blood of breast cancer patients, 1 of 3 from lung cancer and 1 of 2 each from hepatocellular cancer and cancer of the gallbladder were reactive with the MAb. Higher recognition of ROS-DNA by circulating antibodies and DNA isolated from cancer patients by the MAb indicates increased oxidative stress leading to DNA damage. Our results suggest that ROS modification of DNA probably alters its immunogenicity leading to the generation of antibodies to ROS-DNA, probably by the activation of autoreactive cells. The induced antibodies against modified DNA are cross-reactive to native DNA.