Power system voltage control by distributed expert systems

A case study of the application of a distributed control scheme to a power system control is presented. In addition, an investigation has been conducted into voltage control. Combined injection of VAr-compensating devices controlled by distributed expert systems has been proposed as a measure to maintain voltage stability in a power system under heavy loading conditions. A simulation study has been carried out by using five workstations that represent a power system and four VAr-compensating devices. The results demonstrate the effectiveness of the proposed system for voltage recovery     

Gianotti-Crosti syndrome associated with cytomegalovirus antigenemia after bone marrow transplantation

Gianotti-Crosti syndrome (GCS) is characterized by a distinctive self-limiting acral papular or papulovesicular eruption associated with an underlying viral illness. It has not been previously reported in patients post-bone marrow transplantation. We report a 6-year-old Japanese boy who underwent allogeneic bone marrow transplantation from an unrelated donor for acute lymphoblastic leukemia (ALL) in second remission. He had clinical and histopathologic findings characteristic of GCS and evidence of subclinical infection with cytomegalovirus (CMV) detected by CMV antigenemia assay. It is likely that CMV is the causative agent for the GCS in this case.     

The effects of infusion of trieicosapentaenoyl-glycerol emulsion on extravascular lung water during myocardial ischemia and reperfusion in dogs

To test the effects of eicosapentaenoic acid (EPA) infusion on pulmonary edema induced by coronary ligation and reperfusion, extravascular lung water (EVLW) was measured in situ by the thermal-dye double indicator dilution method in dogs. In the control group of five dogs, 30 mL of a 10% soybean oil emulsion was infused through a leg vein. One hour after infusion, the left anterior descending coronary artery below the first diagonal branch was ligated for 15 min and then reperfused for 30 min. In the EPA group, six dogs were similarly treated with an emulsion of a 10% trieicosapentaenoyl-glycerol (90% pure). EVLW, pulmonary capillary wedge pressure, mean pulmonary artery pressure, mean blood pressure, and cardiac index were measured before and 15 min after coronary ligation, and 15 min and 30 min after coronary reperfusion. There were no significant differences in the hemodynamic indices between the two groups. EVLW significantly increased up to two times of baseline during coronary ligation in the control group (P< 0.05) and more during reperfusion (P<0.01), whereas EVLW did not increase in the EPA group. In conclusion, EPA inhibited EVLW accumulation and may be useful for ameliorating one of the ischemia-reperfusion-induced complications, pulmonary edema.     

New bleeding model of additives in a polypropylene film under atmospheric pressure II

Many additives are commercially used to add more favorable qualities to films. The bleeding process by which the additive in a film comes to the surface is considered. A new bleeding model of additives in a polypropylene film under atmospheric pressure was investigated. Solubility and diffusion are found to be important for explaining this bleeding process. It was found that the experimental results were explained more precisely by assuming a two‐step transport process between the crystalline regions and the amorphous ones. The solubilities and diffusion coefficients of UV‐stabilizers such as 2‐(2H‐benzotriazol‐2‐yl)‐4‐(1,1,3,3‐tetramethylbutyl)phenol and 2‐(2H‐benzotriazol‐2‐yl)‐4‐methylphenol were determined at 40°C. The difference between the saturation solubilities and the diffusion coefficients of UV‐stabilizers was discussed by comparing with the results of molecular dynamics (MD) simulation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Realization of the Gallium Triple Point at NMIJ/AIST

The triple point of gallium has been realized by a calorimetric method using capsule-type standard platinum resistance thermometers (CSPRTs) and a small glass cell containing about 97 mmol (6.8 g) of gallium with a nominal purity of 99.99999%. The melting curve shows a very flat and relatively linear dependence on 1/F in the region from 1/F = 1 to 1/F = 20 with a narrow width of the melting curve within 0.1 mK. Also, a large gallium triple-point cell was fabricated for the calibration of client-owned CSPRTs. The gallium triple-point cell consists of a PTFE crucible and a PTFE cap with a re-entrant well and a small vent. The PTFE cell contains 780 g of gallium from the same source as used for the small glass cell. The PTFE cell is completely covered by a stainless-steel jacket with a valve to enable evacuation of the cell. The melting curve of the large cell shows a flat plateau that remains within 0.03 mK over 10 days and that is reproducible within 0.05 mK over 8 months. The calibrated value of a CSPRT obtained using the large cell agrees with that obtained using the small glass cell within the uncertainties of the calibrations.     

Exclusion of a sciatic artery aneurysm and an obturator bypass

This case report describes surgical treatment in a sciatic artery aneurysm with hypoplastic external iliac and femoral arteries. An obturator bypass grafting procedure from the internal iliac artery to the distal sciatic artery was performed after aneurysmal exclusion was achieved by proximal and distal ligation. This method offers an acceptable option for surgery in some types of sciatic artery aneurysms.     

Administration-time-dependent effects of diltiazem on the 24-hour blood pressure profile of essential hypertension patients

Cells of the central nervous system (CNS) normally do not express detectable levels of major histocompatibility complex (MHC) Class I antigens. However, MHC Class I expression can be induced after virus infection. We tested the hypothesis that virus-induced Class I expression is mediated by lymphocytes or cytokines using lymphocyte- and cytokine-deficient mice. We used Theiler's murine encephalomyelitis virus (TMEV), which induces CNS demyelination that maps genetically to the D region of MHC Class I and is associated with high levels of Class I products. TMEV infection of severe combined immunodeficiency (SCID) and recombination activation gene-1-deficient mice, which lack B and T lymphocytes, resulted in equivalent H-2D and H-2K expression in brain and spinal cord, according to analysis of the area and intensity of immunoperoxidase staining. Class I antigens were demonstrated as early as 6 hours after infection, and they were more widely distributed than viral RNA, indicating that expression was induced indirectly via a soluble factor. To determine whether cytokines induced the expression, we infected mice lacking receptors for interferon-alpha/beta (IFN-alpha/beta R (-/-)), interferon-gamma (IFN-gamma R(-/-)), and tumor necrosis factor-alpha (TNFRp55(-/-)). TMEV-infected IFN-gamma R(-/-) and TN-FRp55(-/-) mice expressed Class I antigens in the CNS, whereas IFN-alpha/beta R(-/-) mice did not, establishing that IFN-alpha/beta mediated the expression. In contrast to the equivalent expression in SCID mice, we observed greater area and higher intensity of H-2D versus H-2K antigens in infected SCID mice reconstituted with normal spleen cells. Collectively, the data indicate that after TMEV infection, early generalized MHC Class I expression is mediated by IFN-alpha/beta independently of lymphocytes, but the differential regulation of H-2D over H-2K may be controlled by B and/or T lymphocytes.     

Surface pressure and wind load characteristics on prisms immersed in a simulated transient gust front flow field

Thunderstorm generated gust fronts are responsible for various degrees of structural damage in many areas of the world. However, the resulting impact of gust front winds is not fully understood to such a level that their flow kinematics, dynamics and impact on structures can be quantified with some certainty. Gust front winds are transient in nature and have a flow profile which differs significantly from a typical boundary layer flow field. This study focuses on investigating the effects of this flow profile and its transient nature on the aerodynamics of bluff, prismatic bodies. A gust front type flow field is generated using a multiple fan wind tunnel and the resulting surface pressures are captured on a suite of prismatic models, which vary in size in relationship to the oncoming wind profile. The temporal variations in surface pressures are analyzed using traditional time, frequency and time-frequency domain schemes. Results indicate the changing nature of the surface pressure field in time, highlighting both qualitative and quantitative differences between local and area-averaged pressures under a host of flow profiles.     

Wind field simulation and wind‐induced responses of large wind turbine tower‐blade coupled structure

Herein, by a case study on a 5‐MW wind turbine system developed by Nanjing University of Aeronautics and Astronautics, the wind field simulation and wind‐induced vibration characteristics of wind turbine tower‐blade coupled systems is analyzed. First, the blade‐nacelle‐tower‐basis integrated finite element model with centrifugal forces induced by rotational blades is established. Then, based on a harmony superposition method and the modified blade element‐momentum theory, the fluctuating wind field of tower‐blade coupled systems is simulated, which considers wind shear effect, tower shadow effect, rotational effect, blade‐tower dynamic and model interaction effects. Finally, the wind‐induced dynamic responses and wind vibration coefficients of the wind turbine tower‐blade coupled structure are discussed through the ‘consistent coupled method’ previously proposed by us. The results indicate that the wind‐induced responses of a large wind turbine tower‐blade coupled structure present complicated modal responses and multimode coupling effect. Additionally, the rotational effect would amplify aerodynamic loads on blades with high frequency, wind‐induced dynamic responses and wind vibration coefficients of wind turbine tower. The centrifugal force effect could also amplify natural vibration frequency of the tower‐blade coupled system and reduce the wind‐induced dynamic responses and wind vibration coefficients of wind turbine tower. The research could contribute to wind‐resistant design of structure for a large‐scale wind turbine tower‐blade system. Copyright © 2014 John Wiley & Sons, Ltd.