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A power transformer has complex geometry comparing with other electric machines. So it needs a lot of computing time when we deal with the transient problem such as short-circuit characteristics of a power transformer. In this paper, we proposed an efficient numerical technique to compute transient electromagnetic force of a power transformer during three-phase short-circuit condition. In order to analyze the transient electromagnetic force acting on every disk of transformer windings, we made a simplified axi-symmetric model. First, the transient short-circuit current is calculated by using a short-circuit equation. Next, the transient short-circuit electromagnetic force due to the short-circuit current is computed by finite element method with a simplified axi-symmetric model. The proposed numerical technique is expected to be useful in the short-circuit duty design and structure design of the power transformers. [ABSTRACT FROM AUTHOR]

To investigate the effect of continuous multi-walled carbon nanotubes (MWCNTs) on the thermal and mechanical properties of composites, we propose a fabrication method for a buckypaper-filled flexible composite film prepared by a two-step process involving buckypaper fabrication using vacuum filtration of MWCNTs, and composite film fabrication using the dipping method. The thermal conductivity and tensile strength of the composite film filled with the buckypaper exhibited improved results, respectively 76% and 275% greater than those of the individual MWCNT-filled composite film. It was confirmed that forming continuous MWCNT fillers is an important factor which determines the physical characteristics of the composite film. In light of the study findings, composite films using buckypaper as a filler and polydimethylsiloxane (PDMS) as a flexible matrix have sufficient potential to be applied as a heat-dissipating material, and as a flexible film with high thermal conductivity and excellent mechanical properties. [ABSTRACT FROM AUTHOR]

Aspirin (acetylsalicylic acid) is one of the most widely used therapeutic agents based on its pharmacological actions, including anti-inflammatory, analgesic, anti-pyretic, and anti-thrombotic effects. In this study, we investigated the effects of aspirin on seizure susceptibility and hippocampal neuropathology following pilocarpine-induced status epilepticus (SE). SE was induced by pilocarpine hydrochloride (280 mg/kg, i.p.) administration in C57BL/6 mice (aged 8 weeks). Aspirin was administered daily (15 mg/kg or 150 mg/kg, i.p.) for 10 days starting 3 days before SE, continuing until 6 days after SE. After pilocarpine injection, SE onset time and mortality were recorded. Neuronal cell death was examined using cresyl violet and Fluoro-Jade staining, and glial responses were observed 7 days post SE using immunohistochemistry. In the aspirin-treated group, the onset time of SE was significantly shortened and mortality was markedly increased compared to the control group. However, in this study, aspirin treatment did not affect SE-induced neuronal cell death or astroglial and microglial responses in the hippocampus. In conclusion, these results suggest that the safety of aspirin should be reevaluated in some patients, especially with neurological disorders such as temporal lobe epilepsy. [ABSTRACT FROM AUTHOR]

In this study, cyanidin-3-glucoside (C3G) fraction extracted from the mulberry fruit (Morus alba L.) was investigated for its neuroprotective effects against oxygen-glucose deprivation (OGD) and glutamate-induced cell death in rat primary cortical neurons. Cell membrane damage and mitochondrial function were assessed by LDH release and MTT reduction assays, respectively. A time-course study of OGD-induced cell death of primary cortical neurons at 7 days in vitro (DIV) indicated that neuronal death was OGD duration-dependent. It was also demonstrated that OGD for 3.5 h resulted in approximately 50% cell death, as determined by the LDH release assay. Treatments with mulberry C3G fraction prevented membrane damage and preserved the mitochondrial function of the primary cortical neurons exposed to OGD for 3.5 h in a concentration-dependent manner. Glutamate-induced cell death was more pronounced in DIV-9 and DIV-11 cells than that in DIV-7 neurons, and an application of 50µM glutamate was shown to induce approximately 40% cell death in DIV-9 neurons. Interestingly, treatment with mulberry C3G fraction did not provide a protective effect against glutamate-induced cell death in primary cortical neurons. On the other hand, treatment with mulberry C3G fraction maintained the mitochondrial membrane potential (MMP) in primary cortical neurons exposed to OGD as assessed by the intensity of rhodamine-123 fluorescence. These results therefore suggest that the neuroprotective effects of mulberry C3G fraction are mediated by the maintenance of the MMP and mitochondrial function but not by attenuating glutamate-induced excitotoxicity in rat primary cortical neurons. [ABSTRACT FROM AUTHOR]

Golgi SNAP receptor complex 1 (GS28) has been implicated in vesicular transport between intra-Golgi networks and between endoplasmic reticulum (ER) and Golgi. Additional role(s) of GS28 within cells have not been well characterized. We observed decreased expression of GS28 in rat ischemic hippocampus. In this study, we examined the role of GS28 and its molecular mechanisms in neuronal (SK-N-SH) cell death induced by hydrogen peroxide (H2O2). GS28 siRNA-transfected cells treated with H2O2 showed a significant increase in cytotoxicity under glutathione (GSH)-depleted conditions after pretreatment with buthionine sulfoximine, which corresponded to an increase of intracellular reactive oxygen species (ROS) in the cells. Pretreatment of GS28 siRNA-transfected cells with p38 chemical inhibitor significantly inhibited cytotoxicity; we also observed that p38 was activated in the cells by immunoblot analysis. We confirmed the role of p38 MAPK in cotransfected cells with GS28 siRNA and p38 siRNA in the cell viability assay, flow cytometry, and immunoblot. Involvement of apoptotic or autophagic processes in the cells was not shown in the cell viability, flow cytometry, and immunoblot analyses. However, pretreatment of the cells with necrostatin-1 completely inhibited H2O2-induced cytotoxicity, ROS generation, and p38 activation, indicating that the cell death is necroptotic. Collectively these data imply that H2O2 induces necroptotic cell death in the GS28 siRNA-transfected cells and that the necroptotic signals are mediated by sequential activations in RIP1/p38/ROS. Taken together, these results indicate that GS28 has a protective role in H2O2-induced necroptosis via inhibition of p38 MAPK in GSH-depleted neuronal cells. [ABSTRACT FROM AUTHOR]

The dimensional variation of an injection-molded, semicrystalline polymer part is larger than the variation of an amorphous polymer part because the shrinkage of a crystalline polymer is generally greater than the shrinkage of an amorphous one. We investigated the warpage of film-insert-molded (FIM) specimens to determine the effect of the crystallization behavior on the deformation of FIM parts. More perfect crystalline structures and higher crystallinity developed in the core region of the FIM specimens versus other regions. Relatively imperfect crystalline structures and low crystallinity developed in the adjacent regions of the inserted films, whereas a thin, amorphous skin layer developed in the adjacent regions of the metallic mold wall. The crystallizable substrate in the FIM specimens caused very large warpage because nonuniform shrinkage occurred in the thickness direction of the specimens. Therefore, the warpage of an experimentally prepared FIM poly(butylene terephthalate) specimen was greater than that predicted numerically because of its complex crystallization behavior. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

Back-injection of polymeric liquid to preformed films, also known as film insert molding (FIM), provides the surface quality of polymeric parts. The back-injection material is responsible for mechanical and thermal properties of the part, especially such as stiffness and thermal expansion. In the back-injection molding it is important to ensure that the inserted films are not wrinkled by the injection of molten polymers. In this study, FIM was carried out with utilizing polycarbonate/acrylonitrile butadiene styrene (PC/ABS) alloy and polymethyl methacrylate/acrylonitrile butadiene styrene (PMMA/ABS) film. The wrinkling of films was observed by the atomic force microscope (AFM). Numerical simulations were performed to understand the mechanism of the film wrinkling and optimize the processing conditions of FIM for high precision parts by using commercial packages including Hypermesh™, Moldflow™, and COMSOL™. A critical shear rate for the film wrinkling of a center garnish part was determined based on the deformation energy of plate. It was found that the critical shear rate calculated numerically was in good agreement with that of the film insert molded parts. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Complex automotive parts were produced by film insert molding and the ejected parts were annealed to investigate the viscoelastic deformation. Warpage of the part was predicted by numerical simulation of mold filling, packing, and cooling stages with non‐isothermal three‐dimensional flow analysis. The flow analysis results were transported to a finite element stress analysis program and the stress analysis was performed by using time‐temperature superposition principle to investigate viscoelastic deformation. Predicted residual stresses, viscoelastic deformation, and warpage showed good agreement with experimental results. Thermal shrinkage of the inserted film and relaxation of the residual stress affected the viscoelastic deformation of the part significantly during annealing. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [ABSTRACT FROM AUTHOR]

In this study, experimental and numerical studies were performed to investigate the relationship among the functionalization method, weight fraction of MWCNTs, thermal imidization cycle, and mechanical properties of various PAIMWCNT composite films. Polyamidecoimidemultiwalled carbon nanotube composite films were prepared by solution mixing and film casting. The effects of chemical functionalization and weight fraction of multiwalled carbon nanotubes on thermal imidization and mechanical properties were investigated through experimental and numerical studies. The time needed to achieve sufficient thermal imidization was reduced with increasing multiwalled carbon nanotube content when compared with that of a pure polyamidecoimide film because multiwalled carbon nanotubes have a higher thermal conductivity than pure polyamidecoimide resin. Mechanical properties of pure polyamidecoimide and polyamidecoimidemultiwalled carbon nanotube composite films were increased with increasing imidization time and were improved significantly in the case of the composite film filled with hydrogen peroxide treated multiwalled carbon nanotubes. Both the tensile strength and strain to failure of the multiwalled carbon nanotube filled polyamidecoimide film were increased substantially because multiwalled carbon nanotube dispersion was improved and covalent bonding was formed between multiwalled carbon nanotubes and polyamidecoimide molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [ABSTRACT FROM AUTHOR]

Compression and relaxation behavior of various fiber preforms for resin transfer molding was investigated experimentally through compression, relaxation, and decompression procedures. A simple Maxwell model was used in order to predict the nonlinear compression and relaxation behavior, and numerical simulation was performed for a unit cell of the fiber preform by using the finiteelement method. As the fiber volume fraction is larger than 0.4, compressive stresses acting on the woven fabric increased linearly with increasing fiber volume fraction. A typical hysteresis occurred due to relaxation behavior of the fiber preform during compression and decompression test. It was also found that numerical analysis yields slightly lower displacement field than experimental results under the same compressive force. However, experimental results were in good agreement with the analytic results obtained by considering the viscoelasticity of fiber preforms. [ABSTRACT FROM AUTHOR]

Rectangular plates of the size of 1800 × 600 × 12 mm3and 1200 × 600 × 12 mm3were selected for injection molding and injection compression molding, respectively, in order to investigate warpage characteristics of the large‐sized polymer plates with orthogonal stiffener. To determine the mold system and to reduce warpage of the specimen, numerical analyses for injection molding and injection compression molding were performed by using a commercial simulation code. Experiments were performed to verify the suggested mold system and warpage of the specimen. Relatively large warpage of the injection molded product was observed and small warpage of the injection compression molded product was generated. Compression force of the injection compression molding was only 6% of the clamp force of the injection molding. Warpage of the product was reduced significantly by using the injection compression molding. The injection compression molding will be used to substitute expensive and disused wood forms with inexpensive and recyclable polymer plates for concrete casting. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [ABSTRACT FROM AUTHOR]

Plutonyl(VI) nitrate complexes with N-cyclohexyl-2-pyrrolidone (NCP) and N-neopentyl-2-pyrrolidone (NNpP) were prepared, and their molecular and crystal structures were determined by single crystal X-ray analysis. The obtained compounds have a similar composition, PuO2(NO3)2(NRP)2(NRP = NCP, NNpP), which are analogous to the corresponding UVIcomplexes. Both PuO2(NO3)2(NRP)2complexes show typical structural properties of actinyl(VI) nitrates, that is, hexagonal-bipyramidal geometry consisting of two NRP molecules and two NO3−ions located in trans positions in the equatorial plane of the PuO22骈麷, PuOax= 1.73 Å, Pu−ONRP= 2.38 Å, Pu−ONO3= 2.50 Å, and a bond angle between the Pu−ONRPbond and the carbonyl group of NRP ≈ 135°. PuO2(NO3)2(NNpP)2is isostructural with the corresponding uranium compound, whereas PuO2(NO3)2(NCP)2is not. These findings provide one of criteria in selection of suitable NRP as a precipitation agent for the spent nuclear fuel reprocessing based on the precipitation method from a viewpoint of crystal engineering. [ABSTRACT FROM AUTHOR]

The article discusses film insert molding (FIM), where a film is attached to one side of a mold's walls, followed by the injection of molten polymer. The authors use nonisothermal three dimensional flow analysis to the related packing, filling and cooling stages that occur with FIM. Topics include flow analysis results for the substrate region, a stress analysis program used to analyze viscoelastic stresses, and residual stress distribution in the FIM part. Also discussed is understanding the FIM part's long term behavior when exposed to room temperature.

To examine properties of pentavalent uranium, U(V), we have carried out electrochemical and spectroelectrochemical studies on UO[sub 2](saloph)L [saloph = N,N'-disalicylidene-o-phenylenediaminate, L = dimethyl sulfoxide (DMSO) or N,N-dimethylformamide (DMF)]. The electrochemical reactions of UO[sub 2](saloph)L complexes in L were found to occur quasireversibly. The reduction processes of UO[sub 2](saloph)L complexes were followed spectroelectrochemically by using an optical transparent thin layer electrode cell. It was found that the absorption spectra measured at the applied potentials from 0 to -1.650 V versus ferrocene/ferrocenium ion redox couple (Fc/Fc[sup +]) for UO[sub 2](saloph)DMSO in DMSO have clear isosbestic points and that the evaluated electron stoichiometry equals 1.08. These results indicate that the reduction product of UO[sub 2](saloph)DMSO is [U[sup v]O[sub 2](saloph)DMSO][sup -], which is considerably stable in DMSO. Furthermore, it was clarified that the absorption spectrum of the [U[sup v]O[sub 2](saloph)DMSO][sup -] complex has a very small molar absorptivity in the visible region and characteristic absorption bands due to the 5f[sup 1] orbital at around 750 and 900 nm. For UO[sub 2](saloph)DMF in DMF, the clear isosbestic points were not observed in the similar spectral changes. It is proposed that the UO[sub 2](saloph)DMF complex is reduced to [U[sup v]O[sub 2](satoph)DMF][sup -] accompanied by the dissociation of DMF as a successive reaction. The formal redox potentials of UO[sub 2](saloph)L in L (E[sup 0], vs FclFc[sup +]) for U(VI)/U(V) couple were determined to be -1.550 V for L = DMSO and -1.626 V for L = DMF. [ABSTRACT FROM AUTHOR]

A porous silica-based adsorbent was prepared by impregnating the pores of a silica support with the extractant 1,3-[(2,4-diethylheptylethoxy)oxy]-2,4-crown-6-calix[4]arene (Calix[4]arene-R14) and an additive agent 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (C2mim + NTf2−) as the materials to remove cesium(I) (Cs+) ions from seawater. The as-prepared adsorbent showed excellent adsorption performance toward Cs+ ions, with adsorption equilibrium reached within 2 h and an adsorption amount of 0.196 mmol/g observed. The solution pH, temperature, and the presence of coexisting metal ions were found to have almost no effect on Cs+ adsorption. The adsorption mechanism was considered to proceed via ion exchange between Cs+ and C2mim+. In addition, the particle-induced X-ray emission analysis results further clarified that the adsorbed Cs+ ion species on the adsorbent was in the form of both CsCl and CsBr.

Aiming at selective adsorption and separation of Y(III) from the Y(III)–Sr(II) group in acid solution, a silica-based TODGA impregnated adsorbent [(TODGA+1-dodecanol)/SiO2–P–F600] has been prepared. Batch adsorption experiments were conducted under the effect of contact time, acid concentration, solution temperature, and adsorption capacity etc. Chromatography recovery of more than 90% Y(III) was successfully achieved under elution with 0.01 M DTPA solution in nitric acid adsorption system, and 0.1 M HCl solution in hydrochloride adsorption system, respectively.

A hydrophobic ionic liquid including an amino moiety ([DiOcAPmim][NTf2]) was synthesized. Its extraction behaviors towards Pd(II), Ru(III), Rh(III) were investigated in nitric acid aqueous solution as a function of contact time, effect of concentration of nitric acid, effect of temperature, and effect of co-existing metal ions. The extraction kinetics of Pd(II) was fairly fast and extraction equilibrium can be attained within only 5 min under the [HNO3] = 2.05 M. When [HNO3]< 1 M, the extraction percentage of Pd(II), Ru(III), Rh(III) were all above 80%. When [HNO3] reached 2 M, all of the extraction percentage decreased and in an order of Pd(II)>Ru(III)>Rh(III). When [HNO3]> 2 M, the extraction performance gradually recovered. The effect of temperature can slightly affect the extraction performance of Pd(II). Furthermore, in simulated high-level liquid waste, [DiOcAPmim][NTf2] showed a better preference towards Pd(II) under the interference of various other co-existing metal ions.