Adsorption isotherms of pigments from alkali-refined vegetable oils with clay minerals

Adsorption isotherms of pigments from alkali-refined oils (rapeseed, soybean, wheatgerm, safflower, corn, cottonseed and sunflower) were measured to investigate the applicability of the Langmuir and Freundlich equations and to elucidate the adsorption characteristics of pigments on sepiolites and standard activated clay. The Freundlich equation was more applicable to the experimental adsorption isotherms. The equilibrium amount adsorbed, acidity, pore size distribution and inflection of the Freundlich isotherms could be explained by assuming that pigments were adsorbed on the stronger acid sites in smaller pores at low concentration, and then in the larger ones when the concentration increased. The amount adsorbed increased with a rise in adsorption temperatures from 70 to 110°C, and the heat of adsorption was below 10 kcal/mol. The results indicate that pigments were physically adsorbed on the acid sites activated at higher adsorption temperatures.     

A Brief Survey of Asymmetric MDS and Some Open Problems

Behaviormetrika - A brief review is made of a body of extant asymmetric MDS models and methods, given a one-mode, two-way asymmetric square relational data matrix whose elements are similarity or...     

Possibility of Japanese Cedar Pollen Causing False Positives in the Deep Mycosis Test

Because Japanese cedar pollen (JCP) contains beta-1,3-d-glucan (BG), there is concern that its lingering presence in the atmosphere, especially during its scattering period, may cause false positives in the factor-G-based Limulus amebocyte lysate (LAL) assay used to test for deep mycosis (i.e., G-test). Hence, we examined whether the LAL assay would react positively with substances contained in JCP by using the G-test to measure JCP particles and extracts. BG was purified from the JCP extract on a BG-specific affinity column, and the percentage extractability was measured using three different BG-specific quantitative methods. The G-test detected 0.4 pg BG in a single JCP particle and 10 fg from a single particle in the extract. The percentage extractability of JCP-derived BG was not significantly different among the three quantitative methods. As the JCP particles should technically have been removed during serum separation, they should be less likely to be a direct false-positive factor. However, given that the LAL-assay-positive substances in the JCP extract were not distinguishable by the three BG-specific quantitative methods, we conclude that they may cause the background to rise. Therefore, in Japan false positives arising from JCP contamination should be considered when testing patients for deep mycosis.     

Enantioselective addition Of diketene to aldehydes promoted by chiral schiff base—titanium alkoxide complex. Application to asymmetric synthesis of potential inhibitors of HMG coenzyme reductase

Highly enantioselective addition of diketene to aldehydes was achieved by using novel Schiff base—titanium alkoxide complexes. Up to 92% ee of 5-hydroxy-3-oxoesters was obtained. This procedure provides an efficient method for the asymmetric synthesis of potential inhibitors of HMG coenzyme reductase.     

Simulation of chain length recognition observed in formation of inclusion complex

We carried out Brownian dynamics simulations to investigate the mechanism of chain length recognition observed in the formation of inclusion complexes (ICs) between cyclodextrins (CDs) and polymer chains. In our simulations, we used rings and chains as models to represent CDs and polymer chains, respectively. We used two types of chains with different lengths to determine which chain was preferred by the rings to form ICs. At low concentration of rings, we observed that almost all the rings formed ICs with the long chains. Chain length recognition could be reproduced in our simulation, and it occurred because of the difference in the inclusion time between the long chains and the short chains in the ICs. On the other hand, at high concentration of rings, the number of rings forming ICs with the long chains increased, and pseudo-polyrotaxanes (PPRXs) were formed. ICs were also formed with the short chains, because the inclusion time for each ring contained in the PPRXs reduced with an increase in the number of rings therein, and then, the dissociated rings formed ICs with the short chains. As a result, chain length recognition was not observed. From these results, we conclude that the difference in the inclusion time between the rings and the chains controls chain length recognition.     

A Graphical Technique for Representing the Asymmetric Relationships Between N Objects

Behaviormetrika - A new procedure is discussed which represents the asymmetric relationships between N objects. These relationships must be defined at the interval levels of measurement in...     

Diffusion-preventive Al2O3 layer growth at the interface of plasma-sprayed niobium and FeCrAlY in a tungsten fibre-reinforced high-temperature superalloy composite

The growth mechanism of a diffusion-preventive layer formed at elevated temperatures (∼1500 K) between the plasma-sprayed niobium layer and the plasma-sprayed FeCrAlY matrix in a tungsten fibre-reinforced high-temperature superalloy composite (Nb-coated W fibre/FeCrAlY composite) was studied. The diffusion-preventive layer was identified as α-Al₂O₃ by scanning electron microscopy/electron probe microanalysis, energy dispersive X-ray spectrometry analysis, and X-ray diffraction. Heat-treatment experiments were implemented systematically and it was found that the Al₂O₃ layer was also formed at the plasma-sprayed Nb/rolled FeCrAl interface. No Al₂O₃ layer, however, was formed either at the rolled Nb/plasma-sprayed FeCrAlY interface or at the rolled Nb/rolled FeCrAl interface. In these cases, an intermetallic compound layer was formed instead. A growth mechanism is proposed in which the Al₂O₃ is attributed to a chemical reaction between the residual oxygen in the plasma-sprayed niobium and aluminium in FeCrAlY or FeCrAl. The magnitude of the driving force was evaluated by a new model based on thermodyanamics. Numerical calculations have shown that the proposed growth mechanism is thermodynamically reasonable.