Prediction of Welding Deformation Using the Thermal Elastic-Plastic Finite Element Method by Considering Welding Interpass Temperature.

In this study, we propose a method for predicting welding deformation caused by multi-pass welding using the thermal elastic-plastic finite element method (TEP-FEM) by considering the interpass temperature. This method increases the interpass temperature, which has not been considered in the existing TEP-FEM, from 200 °C to 1000 °C, and simultaneously performs thermal and mechanical analyses. In addition, this method can also evaluate temperature history and the time it takes to weld.

Determination of Optimal Line-Heating Conditions for Flatness Control of Wind Tower Blocks Using Strain as Direct Boundary Method.

The wind tower block is welded with the flange to assemble the wind tower. The inherent strain due to local heating and cooling of the weld affects the flatness of the flange. Therefore, line heating is performed to satisfy the design criteria of the flange flatness, but the work variables depend on the operator's empirical judgment.

Stiffener Design to Maintain Line Heating Efficiency during the Lifting Process Considering Phase Transformation.

In the shipbuilding industry, welding is the main technique used to join steel structures. There is a lifting process, post-welding, that can eliminate the correction effect of line heating. Line heating is reperformed after the lifting process.

Ecotoxicity evaluation of Cu- and Fe-CNT complexes based on the activity of bacterial bioluminescence and seed germination.

The toxic effects of the composites of Fe and Cu with different percentages of CNTs were examined based on the activity of bacterial bioluminescence and seed germination. In terms of the EC values, the toxic effects of Cu on bacterial bioluminescence and seed germination were approximately 2 and 180 times greater than that of Fe, respectively. The toxicity increased with increasing CNT content in the Cu-CNT mixtures for both organisms, whereas opposite results were observed with Fe-CNT mixtures.

Microscale tribological behavior and in vitro biocompatibility of graphene nanoplatelet reinforced alumina.

Graphene nanoplatelets were added as reinforcement to alumina ceramics in order to enhance microscale tribological behavior, which would be beneficial for ceramic-on-ceramic hip implant applications. The reduction in microscale wear is critical to hip implant applications where small amounts of wear debris can be detrimental to patients and to implant performance. The addition of the GNPs lead to improvements in fracture toughness and wear (scratch) resistance of 21% and 39%, respectively.

Electrochemical and in vitro neuronal recording characteristics of multi-electrode arrays surface-modified with electro-co-deposited gold-platinum nanoparticles.

In order to complement the high impedance electrical property of gold nanoparticles (Au NPs) we have performed electro-co-deposition of gold-platinum nanoparticles (Au-Pt NPs) onto the Au multi-electrode array (MEA) and modified the Au-Pt NPs surface with cell adhesive poly-D-lysine via thiol chemistry based covalent binding. The Au-Pt NPs were analyzed to have bimetallic nature not the mixture of Au NPs and Pt NPs by X-ray diffraction analysis and to have impedance value (4.0 × 10(4) Ω (at 1 kHz)) comparable to that of Pt NPs.

In vitro extracellular recording and stimulation performance of nanoporous gold-modified multi-electrode arrays.

Objective: Nanoporous gold (Au) structures can reduce the impedance and enhance the charge injection capability of multi-electrode arrays (MEAs) used for interfacing neuronal networks. Even though there are various nanoporous Au preparation techniques, fabrication of MEA based on low-cost electro-codeposition of Ag:Au has not been performed. In this work, we have modified a Au MEA via the electro-codeposition of Ag:Au alloy, followed by the chemical etching of Ag, and report on the in vitro extracellular recording and stimulation performance of the nanoporous Au-modified MEA.

Variation of nephrotoxicity biomarkers by urinary storage condition in rats.

Recently, there has been an increase in the use of several nephrotoxicity biomarkers in preclinical experiments. In addition, it has been indicated that the result may have been influenced by secondary factors, such as sample storage condition or storage period. In this study, we have assessed the variation in urinary nephrotoxicity biomarkers as a result of urine storage conditions and storage period of the urine.

Characterization of multiwalled carbon nanotube-reinforced hydroxyapatite composites consolidated by spark plasma sintering.

Pure HA and 1, 3, 5, and 10 vol% multiwalled carbon nanotube- (MWNT-) reinforced hydroxyapatite (HA) were consolidated using a spark plasma sintering (SPS) technique. The relative density of pure HA increased with increasing sintering temperature, but that of the MWNT/HA composite reached almost full density at 900°C, and then decreased with further increases in sintering temperature. The relative density of the MWNT/HA composites increased with increasing MWNT content due to the excellent thermal conductivity of MWNTs.

Fine neurite patterns from photocrosslinking of cell-repellent benzophenone copolymer.

We have synthesized photocrosslinkable benzophenone copolymer, Poly(St-co-MBz), and fabricated cell-repellent patterns of Poly(St-co-MBz) on covalently bound poly-D-lysine (PDL) layer via the photocrosslinking. We have successfully obtained fine grid line pattern with line width of 3 μm and fine neurite, presumably axon, patterns with excellent pattern fidelity. We found that benzophenone unit can be crosslinked under the exposure of UV (with the intensity of ∼77 mW/cm² at 280 nm and ∼60 mW/cm² at 365 nm) without photo-oxidative damage to PDL, poly-L-lysine, and polyethyleneimine.

Enhancement of neuronal cell adhesion by covalent binding of poly-D-lysine.

We have prepared the poly-d-lysine (PDL) bound surfaces for neuron cell culture by covalent binding between the poly-d-Lysine and substrates and investigated neuronal cell adhesion properties and cell growth morphology. The number of neuronal cell and the number of neurite per neuronal cell on PDL bound surfaces was much more than those on PDL coated surfaces and also the neuronal cells on PDL bounded surfaces survived a longer time. On the pattern of covalently bound PDL, neuronal cells and their neurites are confined within the grid line leading to patterned neuronal networks with the long-term survival.

One-pot fabrication of various silver nanostructures on substrates using electron beam irradiation.

The one-pot fabrication of various silver nanostructures on substrates is achieved through electron beam irradiation of the surface of silver dodecanethiolate (Ag(I)- SC(12)). The Ag(I)-SC(12) films are simply prepared by spin-coating silver salt and dodecanethiol solution. Various silver nanostructures such as particles, rods, cubes, and networks are prepared from the Ag(I)- SC(12) film with an electron beam voltage from 0.

Size controlled miniscale synthesis of silver nanoparticles using TEM electron beam.

A method for one-pot size-controlled synthesis of silver nanoparticles is proposed and described. The synthesis is based on the reduction of silver-alkanethiolates complexes having highly ordered supramolecular structures through electron beam irradiation in transmission electron microscope (TEM). The method allows synthesis of silver nanoparticles of diameters between 1.

Improved enzymatic hydrolysis yield of rice straw using electron beam irradiation pretreatment.

Rice straw was irradiated using an electron beam at currents and then hydrolyzed with cellulase and beta-glucosidase to produce glucose. The pretreatment by electron beam irradiation (EBI) was found to significantly increase the enzyme digestibility of rice straw. Specifically, when rice straw that was pretreated by EBI at 80 kGy at 0.