Thermal and dynamic mechanical properties of organic–inorganic hybrid composites of itaconate‐containing poly(butylene succinate) and methacrylate‐substituted polysilsesquioxane

Itaconate‐unit‐containing poly(butylene succinate) (PBSI) was synthesized by the reaction of 1,4‐butanediol, succinic acid, and itaconic acid in a molar ratio of 2.0 : 1.0 : 1.0, and the obtained PBSI was reacted with methacryl‐group‐substituted polysilsesquioxane (ME‐PSQ) in the presence of benzoyl peroxide (BPO) at 130°C to produce PBSI/ME‐PSQ hybrid composites. The thermal and dynamic mechanical properties of the PBSI/ME‐PSQ hybrid composites were investigated in comparison with those of PBSI cured at 130°C in the presence of BPO. As a result, the hybrid composites showed a much higher thermal degradation temperature and storage modulus in the rubbery state than the cured PBSI (C‐PBSI). The thermal degradation temperature and storage modulus of the hybrid composites increased with increasing ME‐PSQ content. The glass‐transition temperature, measured by dynamic mechanical analysis of the hybrid composites, somewhat increased with increasing ME‐PSQ content. However, the glass‐transition temperatures of all the hybrid composites were lower than that of C‐PBSI. Although the IR absorption peak related to C?C groups was not detected for C‐PBSI, some olefinic absorption peaks remained for all the hybrid composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influence of anions on the formation of β-FeOOH rusts

The artificial β-FeOOH rusts were synthesized by oxidation of FeCl₂ solutions and hydrolysis of FeCl₃ solutions. Various Na salts such as sulfate, biphosphate, nitrate, and silicate were added to the starting solutions at different anion/Fe molar ratios of 0-0.05. The XRD patterns of the products showed only the diffraction peaks of β-FeOOH. The crystallinity of the products was noticeably reduced by adding and but slightly influenced by adding . The addition of markedly crystallized the products by the hydrolysis of FeCl₃. The N₂ adsorption revealed that the products with were porous particles assembled by β-FeOOH subcrystals. and strongly coordinating to Fe(III) markedly lowered the crystallinity of the products and remained in the formed particles.     

Structure Modification of Alloy Solidified With Electromagnetic Field

A S45C carbon steel has been solidified under different electromagnetic conditions to investigate the effect of the electromagnetic force imposition and its imposing period on the solidified structure in this study.For excitation of the electromagnetic force,a static magnetic field and a direct electric current were simultaneously imposed on a sample under a certain period of the solidification.After the solidification,the microstructures were observed and compared each other.As the results,microstructure of the S45C steel under the simultaneous imposition of a static magnetic field of 1T and a direct electric current of 20A in the latter stage of its solidification was dendritic while it was globular if the electromagnetic force was imposed during the whole solidification period.     

Positron annihilation spectroscopic evidence to demonstrate the flux-enhancement mechanism in morphology-controlled thin-film-composite (TFC) membrane

In this study, positron annihilation lifetime spectroscopy (PALS) is applied to explain the flux-enhancement mechanism in thin-film-composite (TFC) membranes prepared by using dimethyl sulfoxide (DMSO) as an additive in the interfacial polymerization. The TFC membranes show a large increase in water flux, up to 5-fold, compared to nonadditive membrane. Atomic force microscopy (AFM) shows that surface roughness and surface area increase when DMSO in the aqueous phase solution phase works to increase miscibility of the aqueous and the organic phase by reducing the solubility difference of two immiscible solutions. X-ray photoelectron spectroscopy (XPS) reveals the variation of the chemical compositions to the extent that there is a considerable increase in the cross-linked amide linkages of the flux-enhanced TFC membranes. The effects of these structural changes on the molecular-size free volume properties are evaluated by PALS studies. The PALS results are the first to experimentally show that the thin films of cross-linked aromatic polyamide RO membranes are composed of two types of pores having radii of about 2.1-2.4 A from tau3, network pore, and 3.5-4.5 A from tau4, aggregate pore. The increase in the size and number of network pores by means of DMSO addition during interfacial polymerization enhances the water flux notably. The size of aggregate pores also increases and may contribute to enhance water flux, although their number inevitably decreases as the number of network pores becomes increased. Details on the correlations between RO performances and o-Ps lifetime parameters are clearly described based on the pore-flow model of reverse osmosis developed by Sourirajan et al.     

Carrier transport properties in highly ordered smectic liquid crystal phase

We have designed and synthesized a new liquid crystalline phenylbenzothienobenzothiphene derivative, Ph‐BTBT‐4S‐3, in order to investigate the carrier transport properties in highly ordered smectic liquid crystal phase at a wide temperature range lower than room temperature enough to analyze them. Ph‐BTBT‐4S‐3 exhibits smectic E (SmE) phase, which is the one of highly ordered smectic liquid crystal phases, at the wide temperature range from 200°C to under ?130°C. Thanks to its wide temperature range of SmE phase, we could reveal the carrier transport properties in the low temperature range, which were well explained on the basis of Gaussian disorder model having a Gaussian width, σ, of 87 meV, which was larger than those of typical nonpolar liquid crystals of 40?60 meV and was attributed to additional dipole of a thioether group in the side chain.     

Studies on pharmacological activation of human immunoglobulin G by chemical modification and active subfragments. X. Effect of carboxamidemethylated Fc fragment (CM-Fc) from human immunoglobulin G on delayed type hypersensitivity

The anti-allergic activity of the carboxyamidemethylated Fc fragment (CM-Fc) from human serum immunoglobulin G (IgG) was studied using sheep red blood cell-induced delayed type hypersensitivity in mice (SRBC-DTH). CM-Fc suppressed the DTH response when administered 30 min before, or 4 h after the SRBC challenge, but not when administered 8 h or more after the challenge. The Fc fragment showed no activity. CM-Fc administration 30 min before the challenge was unable to suppress the DTH response in the cyclophosphamide (CY)-treated mice. However, adoptive transfer of splenocytes from mice treated with CM-Fc to CY-pretreated mice caused suppression of the SRBC-DTH response. These results suggest that CM-Fc suppressed the DTH response by mediating the function of CY-susceptible cells.     

Prevention of sudden death and the countermeasures--emergency cardiopulmonary resuscitation]

The aim of this study was to analyse inspiratory crackles in patients with Pulmonary Fibrosis (PF) and Bronchiectasis (BE). One case of Chronic Obstructive Pulmonary Disease (COPD) has also been included. The relationships between the time of occurrence of crackles (T) in the breath cycle and the corresponding flow at the mouth (F) and volume (V) have been investigated. The linear correlations between the flow, volume and time have been investigated by Pearson's R-test and the same variables have been analysed by Principal Component Analysis (PCA) in order to verify the effective dimension of these data. The results show a strong correlation between the time of occurrence and the volume in all the examined cases. PCA shows that in all cases F and V account for more than 90% of variation. These results suggest that placing crackles on the flow-volume plane does not cause loss of information.     

Estimation method for unobservable settling vibration of head-positioning control in hard disk drives

To improve reliability in hard disk drives, we proposed an estimation method for unobservable settling vibration in head-positioning control systems. Our proposed method uses both observability and excitability of mechanical vibrations in settling time of a track-seeking control. To see the observability, we employed the estimation method of unobservable amplitude of oscillations caused by mechanical resonances. To see the excitability, we also employed the Shock Response Spectrum (SRS) analysis that can handle the transient characteristics of mechanical vibrations. Simulations and experiments results on the track-seeking control showed that the results of our proposed method were good approximate solutions of the unobservable settling vibrations. This means that we can estimate the risk of the unobservable settling vibrations which may lead to destruction of user data in hard disk drives by using the proposed method. As a result, we can chose the best suited solution to avoid unobservable vibrations in the head-positioning control systems.     

Isolation and characterization of a soluble and thermostable phosphite dehydrogenase from Ralstonia sp. strain 4506

Phosphite dehydrogenase (PtxD), which catalyzes the nearly irreversible oxidation of phosphite to phosphate with the concomitant reduction of NAD(+) to NADH, has great potential for NADH regeneration in industrial biocatalysts. Here, we isolated a soil bacterium, Ralstonia sp. strain 4506, that grew at 45°C on a minimal medium containing phosphite as the sole source of phosphorus. A recombinant PtxD of Ralstonia sp. (PtxD(R4506)) appeared in the soluble fraction in Escherichia coli. The purified PtxD(R4506) showed 6.7-fold greater catalytic efficiency (V(max)/K(m)) than the first characterized PtxD of Pseudomonas stutzeri (PtxD(PS)). Moreover, the purified PtxD(R4506) showed maximum activity at 50°C, and its half-life of thermal inactivation at 45°C was 80.5h, which is approximately 3,450-fold greater than that of PtxD(PS). Therefore, we concluded that PtxD(R4506), which shows high catalytic efficiency, solubility, and thermostability, would be useful for NADH regeneration applications.     

Ti-Rich Barrier Layers Self-Formed on Porous Low-k Layers Using Cu(1?at.%?Ti) Alloy Films

To investigate the applicability of the technique of barrier self-formation using Cu(Ti) alloy films on porous low-k dielectric layers, Cu(1 at.% Ti) alloy films were deposited on porous SiOCH (low-k) dielectric layers in samples with and without ~6.5-nm-thick SiCN pore seals. Ti-rich barrier layers successfully self-formed on the porous low-k layer of both sample types after annealing in Ar for 2 h at 400°C to 600°C. The Ti-rich barrier layers consisted of amorphous Ti oxides and polycrystalline TiC for the samples without pore sealing, and amorphous TiN, TiC, and Ti oxides for the pore-sealed samples. The amorphous TiN originated from reaction of Ti atoms with the pore seal, and formed beneath the Cu alloy films. This may explain two peaks of Ti segregation at the interface that appeared in Rutherford backscattering spectroscopy (RBS) profiles, and suggests that the Ti-rich barrier layers self-formed by the reaction of Ti atoms with the pore seal and porous low-k layers separately. The total molar amount of Ti atoms segregated at the interface in the pore-sealed samples was larger than that in the samples without pore sealing, resulting in lower resistivity. On the other hand, resistivity of the Cu alloy films annealed on the porous low-k layers was lower than that annealed on the nonporous low-k layers. Coarser Cu columnar grains were observed in the Cu alloy films annealed on the porous low-k layers, although the molar amount of Ti atoms segregated at the interface was similar in both sample types after annealing. The cause could be faster reaction of the Ti atoms with the porous dielectric layers.