Observation of the electrorheological effect of siliconeoil/polymer particles suspension

A liquid insulator that suspends small particles is one of the electrorheological fluids (ERF) whose apparent viscosity becomes larger under an electric field because of the formation of particle chains. Since many possible applications of ERF are expected, the development of a more practical ERF is required. We have investigated the ER effect of silicone oil in which small particles are suspended. Silica particles, silica particles coated by conductive polymer film, and polymer particles (microcrystalline cellulose), with a diameter between 5~100 μm, are investigated in order to clarify the difference between suspending materials. To measure the ER effect, a rotational viscometer was constructed. It became clear that the shear stress for cellulose particles is much stronger than that for other particles because of its peculiar particle chain formation due to the particle shape     

Effect of surface roughness and surface modification of indium tin oxide electrode on its potential response to tryptophan

The effect of surface modification of indium tin oxide (ITO) electrode on its potential response to tryptophan was investigated for ITO substrates with different surface roughness. It was found that a small difference in surface roughness, between ∼1 and ∼2 nm of R_a evaluated by atomic force microscopy, affects the rest potential of ITO electrode in the electrolyte. A slight difference in In:Sn ratio at the near surface of the ITO substrates, measured by angle-resolved X-ray photoelectron spectrometry and Auger electron spectroscopy is remarkable, and considered to relate with surface roughness. Interestingly, successive modification of the ITO surface with aminopropylsilane and disuccinimidyl suberate, of which essentiality to the potential response to indole compounds we previously reported, improved the stability of the rest potential and enabled the electrodes to respond to tryptophan in case of specimens with R_a values ranging between ∼2 and ∼3 nm but not for those with R_a of ∼1 nm. It was suggested that there are optimum values of effective work function of ITO for specific potential response to tryptophan, which can be obtained by the successive modification of ITO surface.     

Study on effects of solar radiation and rain on shrinkage, shrinkage cracking and creep of concrete

In this paper, the effects of actual environmental actions on shrinkage, creep and shrinkage cracking of concrete are studied comprehensively. Prismatic specimens of plain concrete were exposed to three sets of artificial outdoor conditions with or without solar radiation and rain to examine the shrinkage. For the purpose of studying shrinkage cracking behavior, prismatic concrete specimens with reinforcing steel were also subjected to the above conditions at the same time. The shrinkage behavior is described focusing on the effects of solar radiation and rain based on the moisture loss. The significant environment actions to induce shrinkage cracks are investigated from viewpoints of the amount of the shrinkage and the tensile strength. Finally, specific compressive creep behavior according to solar radiation and rainfall is discussed. It is found that rain can greatly inhibit the progresses of concrete shrinkage and creep while solar radiation is likely to promote shrinkage cracking and creep.     

Effect of agglomeration of triacylglycerols on the stabilization of a model cream

This study has been carried out on solidification of a model cream using palm oil as a sole fat source. It was found that the addition of 1‐palmitoylglycerol to palm oil promoted the solidification of the model cream while the addition of 1‐oleoylglycerol had no such effect. Solid fat content of palm oil in the cream with 1‐palmitoylglycerol was found to be lower than those of palm oil and palm oil with 1‐oleoylglycerol after cooling from 60 to 5 °C. Crystallization behaviors of bulk palm oil and mixture of 1, 3‐dipalmitoyl‐ 2‐oleoyl‐glycerol (POP) and 1‐palmitoyl‐2, 3‐dioleoyl‐glycerol (POO) were then studied in the presence of monoacylglycerols. Formation of granular crystals was observed for palm oil and POP/POO mixture in the presence of 1‐palmitoylglycerol. HPLC of the granular crystals revealed that agglomeration of higher melting point triacylglycerols (TAGs) around 1‐palmitolyglycerol took place, which promoted the formation of granular crystals. It was suggested that the agglomeration of higher melting point TAGs around 1‐palmitoylglycerol which was preferentially adsorbed at the oil‐water interface of oil droplets in the model cream led to destabilization of oil‐in‐water emulsion and the solidification of the model cream. At the same time, it was suggested that the fatty acid moiety of emulsifiers played an important role in the agglomeration of TAGs and stabilization of o/w emulsions.     

Local Dynamics of Adhesives in Aggressive Environment in the Pre-Damage Stage

Molecular aspects of chemical and physical changes in adhesive joints caused by absorbed moisture were investigated. The focus was on the pre-damage stage that precedes the formation of voids and microcracks. A model and a commercial epoxy-amine formulation were studied. Local dynamics were monitored by broad-band dielectric relaxation spectroscopy (DRS). One portion of the absorbed water does not form hydrogen bonds with the network and gives rise to a fast relaxation process (termed γ) with activation energy of 28 kJ/mol. The local β dynamics are slowed down by the interactions between water and various sites on the network that include the ether oxygen, the hydroxyl group and the tertiary amine nitrogen. One particularly significant finding is that the average relaxation time for the β process above 20°C is of the order of nanoseconds or less and, hence, the detection and monitoring of this process hinges upon the ability to perform high-precision DRS at frequencies above 1 MHz. This is an important consideration in the ongoing efforts aimed at the implementation of DRS as nondestructive inspection (NDI) tool for adhesive joints.     

Capability of Utilizing CYP3A5 Polymorphisms to Predict Therapeutic Dosage of Tacrolimus at Early Stage Post-Renal Transplantation

While CYP3A5 polymorphisms are used to predict the initial dosage of tacrolimus therapy, the predictive capability of genetic information for dosing at early stage post-renal transplantation is unknown. We investigated the influence of polymorphisms over time. An initial oral dose of modified-release once-daily tacrolimus formulation (0.20 mg/kg) was administered to 50 Japanese renal transplant patients every 24 h. Stepwise multiple linear regression analysis for tacrolimus dosing was performed each week to determine the effect of patient clinical characteristics. The dose-adjusted trough concentration was approximately 70% higher for patients with the CYP3A5*3/*3 than patients with the CYP3A5*1 allele before the second pre-transplantation tacrolimus dose (0.97 (0.78–1.17) vs. 0.59 (0.45–0.87) ng/mL/mg; p < 0.001). The contribution of genetic factors (CYP3A5*1 or *3) for tacrolimus dosing showed increased variation from Day 14 to Day 28 after transplantation: 7.2%, 18.4% and 19.5% on Days 14, 21 and 28, respectively. The influence of CYP3A5 polymorphisms on the tacrolimus maintenance dosage became evident after Day 14 post-transplantation, although the tacrolimus dosage was determined based only on patient body weight for the first three days after surgery. Tacrolimus dosage starting with the initial administration should be individualized using the CYP3A5 genotype information.     

Poly(N‐isopropylacrylamide) gel‐based macroporous monolith for continuous‐flow recovery of palladium(II) ions

Macroporous monoliths, composed of thermoresponsive, tertiary‐aminated, and crosslinking monomers, were prepared for continuous‐flow separation of palladium(II) ions. N ‐Isopropylacrylamide was required to form the porous structure in the monoliths, indicating that the mechanism of porous structure formation involved polymerization‐induced phase separation of the poly(N ‐isopropylacrylamide) gel. Tertiary‐aminated monoliths showed adsorption selectivity for palladium(II) ions in hydrochloric media, compared with copper(II) ions. The maximum capacities of the monoliths with tertiary amine contents of 10, 20, 30, and 70 mol % for palladium(II) ions were 0.6, 1.1, 1.3, and 2.3 mmol/g, respectively. Darcy's permeabilities of water through the macroporous monolith were 10^?14 to 10^?13 m², and those were comparable to that through a commercially available membrane filter with a pore size of several micrometers. In the continuous‐flow process, the macroporous monolith with tertiary amine selectively adsorbed palladium(II) ions in the coexistence of copper(II) ions with 10 times higher concentration than the palladium(II) ions. The palladium(II) ions were eluted from the macroporous monolith, and the concentration of palladium(II) ions in the eluate was up to 45 times of that in the feed solution. The average enrichment factor and total recovery percentage of palladium(II) ions were 8.7 times and 95%, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44385.     

Effect of crosslinking structure on sorption of CO2 in photocrosslinked PVCA film

The sorption behavior of CO₂ gas in photocrosslinked poly(vinyl cinnamate) film was examined under atmospheric pressure. The sorption isotherm was well described by the Langmuir equation, suggesting that sorption of CO₂ is mainly governed by adsorption in the microvoids. The amount of sorbed CO₂ was significantly affected by the degree of crosslinking. The CO₂ sorption was enhanced at a lower degree of crosslinking but was decreased at a higher degree of crosslinking. The unexpected increase in the amount of adsorbed CO₂ correlated with the increase in the number of microvoids that occurred as a result of the crosslinking reaction. However, further crosslinking led to a decrease in the mean size of the microvoids. The smaller microvoids, in comparison to CO₂ molecules, did not act as adsorption sites, so that the amount of sorbed CO₂ decreased. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1744–1750, 2000     

Synthesis of acetonitrile and related compounds from CO-H2-NH3 over Mo/SiO2

In the reaction of CO-H₂-NH₃ on Mo/SiO₂ catalysts, HCN is formed and is considered to be the principal intermediate for the formation of CH₃CN. At low temperature methylamine is also formed.