Alternative Surface-Mounted Permanent Magnet Topology for Reducing Voltage and Torque Harmonics in Shaft Generators

Traditional diesel generators on a merchant ship, composed of a wound rotor synchronous generator and a four-stroke diesel engine, supply electrical power for various loads. Recently, shaft generators for merchant ships have been increasingly replacing diesel generators to reduce CO2 emissions through fuel efficiency improvement. In particular, permanent magnet synchronous generators have replaced induction generators due to their high-efficiency characteristics at light loads. The surface-mounted permanent magnet rotor can be a suitable topology owing to the relatively short constant power range. This generator can also operate as a motor according to the propulsion mode, so minimizing the harmonics of the induced voltage with the torque pulsation being essential. This paper proposes an alternative surface permanent magnet topology. Three magnets comprise one pole, with one bread-loaf magnet and two rectangular magnets. It helps to simplify the magnetization and assembly of the rotor because of the flat bottom shape of the magnet. Due to the low remanence of two rectangular magnets at the pole edge, this rotor structure effectively makes the air-gap magnetic flux density sinusoidal with production costs reduced. The step-skew suppresses higher-order harmonics. The total harmonic distortion comparison of the two-dimensional finite element analysis and the no-load test result shows under 6% difference from the interior permanent magnet prototype machine. A comparison of harmonic characteristics with other rotors shows that the proposed modular pole has sufficient competitiveness compared to the tapered bread-loaf type. It can be applied as a substitute for the tapered bread-loaf magnet in direct-drive ship propulsion systems and is expected to shorten the manufacturing process and time

Tag Interference Based Mobile Object Tracking with Passive UHF RFID System

This paper proposes a novel method that enables location sensing for a mobile object by utilizing deployed passive UHF Radio Frequency Identification (RFID) tags and a stationary RFID reader. In order to estimate the mobile object location, the proposed method utilizes the second order under damped system based tag to tag interference model. The empirical study using RFID systems and a mobile robot verifies the effectiveness and performance of the proposed method. © Springer-Verlag Berlin Heidelberg 2015

Glycolaldehyde-derived advanced glycation end products (glycol-AGEs)-induced vascular smooth muscle cell dysfunction is regulated by the AGES-receptor (RAGE) axis in endothelium

<p>Advanced glycation end-products (AGEs) are involved in the development of vascular smooth muscle cell (VSMC) dysfunction and the progression of atherosclerosis. However, AGEs may indirectly affect VSMCs via AGEs-induced signal transduction between monocytes and human umbilical endothelial cells (HUVECs), rather than having a direct influence. This study was designed to elucidate the signaling pathway underlying AGEs-RAGE axis influence on VSMC dysfunction using a co-culture system with monocytes, HUVECs and VSMCs. AGEs stimulated production of reactive oxygen species and pro-inflammatory mediators such as tumor necrosis factor-α and interleukin-1β via extracellular-signal-regulated kinases phosphorylation and nuclear factor-κB activation in HUVECs. It was observed that AGEs-induced pro-inflammatory cytokines increase VSMC proliferation, inflammation and vascular remodeling in the co-culture system. This result implies that RAGE plays a role in AGEs-induced VSMC dysfunction. We suggest that the regulation of signal transduction via the AGEs-RAGE axis in the endothelium can be a therapeutic target for preventing atherosclerosis.</p

Additional file 1: of Plantamajoside from Plantago asiatica modulates human umbilical vein endothelial cell dysfunction by glyceraldehyde-induced AGEs via MAPK/NF-κB

Figure S1. Advanced glycation end-product formation. Bovine serum albumin and glyceraldehyde were mixed at 37 °C in the dark for 7 days. The fluorescence was measured using fluorescence intensity set at excitation 370 nm and emission 440 nm. (DOCX 71 kb

Antarctic Krill Oil Diet Protects against Lipopolysaccharide-Induced Oxidative Stress, Neuroinflammation and Cognitive Impairment

Oxidative stress and neuroinflammation are implicated in the development and pathogenesis of Alzheimer’s disease (AD). Here, we investigated the anti-inflammatory and antioxidative effects of krill oil. Oil from Euphausia superba (Antarctic krill), an Antarctic marine species, is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We examined whether krill oil diet (80 mg/kg/day for one month) prevents amyloidogenesis and cognitive impairment induced by intraperitoneal lipopolysaccharide (LPS) (250 µg/kg, seven times daily) injections in AD mice model and found that krill oil treatment inhibited the LPS-induced memory loss. We also found that krill oil treatment inhibited the LPS-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and decreased reactive oxygen species (ROS) and malondialdehyde levels. Krill oil also suppresses IκB degradation as well as p50 and p65 translocation into the nuclei of LPS-injected mice brain cells. In association with the inhibitory effect on neuroinflammation and oxidative stress, krill oil suppressed amyloid beta (1–42) peptide generation by the down-regulating APP and BACE1 expression in vivo. We found that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (50 and 100 µM) dose-dependently decreased LPS-induced nitric oxide and ROS generation, and COX-2 and iNOS expression as well as nuclear factor-κB activity in cultured microglial BV-2 cells. These results suggest that krill oil ameliorated impairment via anti-inflammatory, antioxidative, and anti-amyloidogenic mechanisms