Seismic response analysis of soil-structure interactive system using a coupled three-dimensional FE-IE method

This paper proposes a slightly new three-dimensional radial-shaped dynamic infinite elements fully coupled to finite elements for an analysis of soil-structure interaction system in a horizontally layered medium. We then deal with a seismic analysis technique for a three-dimensional soil-structure interactive system, based on the coupled finite-infinite method in frequency domain. The dynamic infinite elements are simulated for the unbounded domain with wave functions propagating multi-generated wave components. The accuracy of the dynamic infinite element and effectiveness of the seismic analysis technique may be demonstrated through a typical compliance analysis of square surface footing, an L-shaped mat concrete footing on layered soil medium and two kinds of practical seismic analysis tests. The practical analyses are (1) a site response analysis of the well-known Hualien site excited by all travelling wave components (primary, shear, Rayleigh waves) and (2) a generation of a floor response spectrum of a nuclear power plant. The obtained dynamic results show good agreement compared with the measured response data and numerical values of other soil-structure interaction analysis package.     

Studies on the analyses for the scale of FGD process

During the period of preventive maintenance of the Ulsan power plant, the scale was sampled from riser pipes, sparger pipes and other important parts in the FGD facilities. Various analyses such as concentration analysis, surface morphology, and crystal structure have been performed on the scale sample. The riser pipe scale was a gypsum dihydrate form. The sparger pipe scale was different from two units, namely, gypsum dihydrate form was obtained from that of unit 6; on the other hand, 1 to 1 ratio of gypsum dihydrate form and anhydrate form was elucidated from that of unit 4. Next, the analyses of GCP spray nozzle head scale, gas-cooling zone scale, and BUF inlet duct scale were focused on the effect of base material. On the basis of the analytical results, we expect to elucidate the formation process of the scale, and finally to improve the FGD process.     

Cellular toxicity of inorganic hydroxide nanoparticles

Layered double hydroxides (LDHs), anionic clays, have attracted increasing interest as nanovehicles for delivering genes, drugs, and bio-active molecules into cells. However, no attempts have been made to evaluate the potential undesirable effects of LDH nanoparticles. The cytotoxicity of LDHs with different chemical compositions (ZnAl- and MgAl-LDH) was systematically evaluated in various cell types, such as human normal cells, carcinoma cells, and red blood cells, by measuring cell viability, cell proliferation, membrane damage, and hemolytic effect. No significant cytotoxic effects could be seen in both cases, but ZnAl-LDH was determined to be slightly more toxic than MgAl-LDH in terms of membrane damage and hemolysis induction. It is, therefore, expected that LDHs could be promising candidates for novel inorganic drug delivery carriers.     

Synthesis and characterization of CLEA-lysozyme immobilized PS/PSMA nanofiber

Using 0.2% glutaraldehyde as the cross-linker, lysozyme was covalently immobilized onto electrospun polystyrene/poly(styrene-co-maleic anhydride) (PS/PSMA) nanofibers as cross-linked enzyme aggregates (CLEA). The lysozyme capacity of PS/PSMA nanofibers under optimal condition was 57.6 mg/g of nanofibers. Various parameters were used to evaluate the stability of the immobilized CLEA-lysozyme. Compared to free enzyme, the immobilized CLEA-lysozyme exhibited its optimal enzymatic activity at higher temperature and pH. The immobilized CLEA-lysozyme maintained more than 78% of its initial activity during 30 days of storage period. Additionally, the immobilized CLEA-lysozyme presented a high antibacterial activity against Staphylococcus aureus. The durability determinations of such nanofibers showed 90.3% retention of the initial lysozyme activity after 80 consecutive reuses, and 81.2% of bacteriostasis ratio after 10 cycles. The results of this study suggest that CLEA-lysozyme immobilized nanofiber which can stabilize its enzymatic activity through cross-linking immobilization can be beneficial for various antibacterial processes.     

Molecular Basis for the Enantio‐ and Diastereoselectivity of Burkholderia cepacia Lipase toward γ‐Butyrolactone Primary Alcohols

Burkholderia cepacia lipase (BCL) shows high enantioselectivity toward chiral primary alcohols, but this enantioselectivity is often unpredictable, especially for substrates that contain an oxygen at the stereocenter. For example, BCL resolves β‐substituted‐γ‐acetyloxymethyl‐γ‐butyrolactones (acetates of a chiral primary alcohol) by hydrolysis of the acetate, but the enantioselectivity varies with the nature and orientation of the β‐alkyl substituent. BCL favors the (R)‐primary alcohol when the β‐alkyl substituent is hydrogen (E=30) or trans methyl (E=38), but the (S)‐primary alcohol when it is cis methyl (E=145). To rationalize this unusual selectivity, we used a combination of experiments to show the importance of polar interactions and modeling to reveal differences in orientations of the enantiomers. Removal of either the lactone carbonyl in the substrate or the polar side chains in the enzyme by using a related enzyme without these side chains decreased the enantioselectivity at least four‐fold. Modeling revealed that the slow enantiomers do not bind by exchanging the location of two substituents relative to the fast enantiomer. Instead, three substituents remain in the same region, but the fourth substituent, hydrogen, inverts to a new location, like an umbrella in a strong wind. In this orientation the favored stereoisomers have similar shapes, thus accounting for the unusual stereoselectivity. The ratio of catalytically productive orientations for the fast vs. slow enantiomers in a molecular dynamic simulation correlated (R²=0.82) with the degree of enantioselectivity including the case where the enantioselectivity reversed. Weighting this ratio by the ratio of H‐bonds in the polar interaction to account for different binding strengths improved the correlation with the measured enantioselectivity to R²=0.97. The modeling identifies key interactions responsible for high enantioselectivity in this class of substrates.

     

Rational Ligand Design of Heteroleptic Iridium (III) Complexes toward Nearly Perfect Horizontal Dipole Orientation for Highly Efficient Red-Emitting Phosphorescent Organic Light-Emitting Diodes

The horizontal orientation of the transition dipole moment of the phosphorescent emitters is understood to be an important factor to enhance the external quantum efficiency (EQE) of organic light-emitting diodes by improving light out-coupling in optical microcavity structures. Here, red-emitting heteroleptic iridium (III) complexes exhibiting an extremely high horizontal ratio of emitting dipole orientation (EDO) and photoluminescence quantum yield (PLQY), as well as longer device operational lifetime, without scarifying any other photophysical properties are reported. The systematic molecular design of main and ancillary ligands in heteroleptic iridium complexes leads to the achievement of both a horizontal EDO of 92% and a PLQY of 98% in the red-emitting phosphorescent devices along with a shorter exciton decay time of 0.71 µs. Accordingly, the red-emitting devices show excellent performances of maximum EQE of 32% and low-efficiency roll-off with the 1931 Commission Internationale de L′Eclariage coordinates of (0.66, 0.34). Therefore, this approach opens the way for further development of new red-emitting iridium complexes pushing the device efficiency toward the theoretical limits.