Mass transfer in polycrystalline ytterbium monosilicate under oxygen potential gradients at high temperatures

Mass transfer in polycrystalline Yb₂SiO₅ wafers with precise composition control was evaluated and analyzed by oxygen permeation experiments at high temperatures using an oxygen tracer. Oxygen permeation proceeded due to mutual grain boundary diffusion of oxide ions and Yb ions without synergistic effects such as acceleration or suppression. The oxygen shielding properties of Yb₂SiO₅ were compared with those of the other line compounds such as Yb₂Si₂O₇ and Al₂O₃ based on the determined mass transfer parameters. It was found that the more preferentially an oxide ion diffuses in the grain boundary compared to the interior of the grain, the greater the effect of suppressing the movement of the oxide ion by applying an oxygen potential gradient becomes.     

Production of Ceramic Green Bodies Using a Microwave-Reactive Organic Binder

Because the pyrolysis of organic substances can result in the emission of harmful pollutant gases, a reduction in the use of organic binders is one aim of today's ceramics industry. A novel ceramic-forming process was developed that requires considerably less organic binder than conventional techniques. The process involves immobilizing reactive molecules on the surfaces of the particles, which on subsequent irradiation with microwaves, form bridges that bind the entire particle assembly together. The chemical forces involved produce strong bonds, resulting in a significant reduction in the amount of organic binder that is required to maintain the shape of the ceramic green body. This method will help to decrease emissions of harmful gases produced from pyrolysis of the binder.     

Network formation and swelling behavior of photosensitive poly(vinyl alcohol) gels prepared by photogenerated crosslinking

Poly (vinyl alcohol) with pendent styrylpyridinium groups (SbQ) is insolubilized by photoirradiation. An association takes place in SbQ groups. The association of polymer chains becomes marked with increasing the number of SbQ groups. Mainly intermolecular crosslinks were formed. Transparent and homogeneous macrogels consisting of several intermolecular crosslinks are obtained. The proportion of the free water to the bound water in PVA-SbQ gels was 3.3?2.9 despite of the large change in conversion of photodimerization of SbQ groups, x=0.27?0.58. The water uptake after swelling of the gels in water increased 6–27 times compared to the original weight at pH=7. The higher the degree of photocrosslinking, the lower was the degree of swelling. The water diffusion coefficients, D, were (2.2?5.8) × 10^?5 cm² S^?1 for a 88% saponified PVA with 1 . 3 mol% SbQ groups. The volume of the gel increased discontinuously about 10-fold for the 99% saponified PVA with 0 . 096 mol% SbQ and 51% water (49% acetone). The acetone concentration at the transition decreased with increasing the degree of saponification of the PVA.     

A novel agglomeration granulating system utilizing a centrifugal-fluidizing drive

Necessary conditions were studied for the optimum operation of agglomeration granulation. The mechanisms that would realize these conditions were investigated by several experiments.On the basis of the results obtained, a novel granulating system involving a surface wetness control mechanism has been developed.The present paper describes the mixing and dispersing characteristics of the coating vessel, the detection method for wetness control, the particular spraying units, and the operating conditions thereof, together with the characteristics of this newly developed powder coating granulation system.This system has been shown to provide an easy and reproducible granulating technique even when products below 1 mm in size are required.     

Molecular motions of non-crystalline poly(aryl ether-ether-ketone) PEEK and influence of elecron beam irradiation

The dynamic mechanical relaxation of non-crystalline poly(aryl ether-ether-ketone) PEEK and the one irradiated with electron beam were studied. The three distinct γ, β, α′ relaxation maxima were observed in unirradiated PEEK from low to high temperature. It was revealed from the study on the irradiation effects that three different molecular processes are overlapped in γ relaxation peak, i.e., molecular motion of water bound to main chain (peak temperature; at ?100°C), local motion of main chain (at ?80°C), and local mode of the aligned and/or oriented moiety (at ?40°C). The β relaxation connected with the glass transition occurred at 150°C and it shifted to higher temperature by irradiation. The α′ relaxation which can be attributed to rearrangement of molecular chain due to crystallization was observed in unirradiated PEEK ～ 180°C and its magnitude decreased with the increase in irradiation dose. This effect indicates the formation of structures inhibiting crystallization such as crosslinking and/or short branching during irradiation. A new relaxation, β′, appeared in the temperature range of 40° to 100°C by irradiation and its magnitude increased with dose. This relaxation was attributed to rearrangement of molecular chain from loosened packing around chain ends, which were introduced into the non-crystalline region by chain scission under irradiation, to more rigid molecular packing, From these observations, we proposed that deterioration in mechanical properties of non-crystalline PEEK by high energy electron beam was brought about not only by chain scission but structural changes such as crosslinking and/or branching in the main chain.     

Experimental design to evaluate properties of electrospun fibers of zein/poly (ethylene oxide) for biomaterial applications

The production of polymer fibers from the combination of zein and PEO might have great potential in the field of biomaterial. Zein/PEO fibers were obtained in this work through solution electrospinning. An experimental design, 2^4-1, was used for evaluating the influences of PEO content in the blend, distance from the needle tip to the collector, applied electric voltage and solution flow for average fiber diameter and relative-yield process. Beyond this, the relationship between PEO content in the blend and the fiber properties were evaluated through FTIR, DSC, TG, tensile tests, and cytotoxic tests. The factor that exerts the greatest effect on the average fiber diameter response was the electrical voltage. The increase in PEO content in the blend decreased the thermal stability and increased the degree of the fibers' crystallinity. The mechanical tests showed that fibers with higher elongation were obtained at richer PEO blends. The fibers presented cytocompatible characteristics.     

Influence of chromium on the local structure and morphology of ferric oxyhydroxides

The extended X-ray absorption fine structure (EXAFS) method and transmission electron microscopy (TEM) have been used for characterizing the local structure and morphology of ferric oxyhydroxides, α-FeOOH and γ-FeOOH, with and without chromium. These ferric oxyhydroxide powders were prepared from aqueous solutions containing iron and chromium ions. Radial structural functions for iron obtained by Fe K edge EXAFS spectra showed that the linkage of structural units formed by FeO₆ octahedra in γ-FeOOH is distorted by chromium addition, while such distortion in α-FeOOH is not clearly detected. On the other hand, Cr K edge EXAFS spectra showed that the local structure around chromium does not necessarily correspond to the local structure around of iron, which is observed by Fe K edge EXAFS spectra. This suggests that the structural units containing iron and chromium are heterogeneously distributed in these ferric oxyhydroxides. The local structural information was discussed coupled with morphological features of these ferric oxyhydroxides observed by TEM.     

Robust comprehension of natural language instructions by a domestic service robot

We present a method through which domestic service robots can comprehend natural language instructions. For each action type, a variety of natural language expressions can be used, for example, the instruction, ‘Go to the kitchen’ can also be expressed as ‘Move to the kitchen.’ We are of the view that natural language instructions are intuitive and, therefore, constitute one of the most user-friendly robot instruction methods. In this paper, we propose a method that enables robots to comprehend instructions spoken by a human user in his/her natural language. The proposed method combines action-type classification, which is based on a support vector machine, and slot extraction, which is based on conditional random fields, both of which are required in order for a robot to execute an action. Further, by considering the co-occurrence relationship between the action type and the slots along with the speech recognition score, the proposed method can avoid degradation of the robot’s comprehension accuracy in noisy environments, where inaccurate speech recognition can be problematic. We conducted experiments using a Japanese instruction data-set collected using a questionnaire-based survey. Experimental results show that the robot’s comprehension accuracy is higher in a noisy environment using our method than when using a baseline method with only a 1-best speech recognition result.     

Polyphenols Extracted from Black Tea (Camellia sinensis) Residue by Hot‐Compressed Water and Their Inhibitory Effect on Pancreatic Lipase in vitro

Abstract: Polyphenols, retained in black tea wastes following the commercial production of tea beverages, represent an underutilized resource. The purpose of this study was to investigate the potential use of hot‐compressed water (HCW) for the extraction of pancreatic lipase‐inhibiting polyphenols from black tea residues. Black tea residues were treated with HCW at 10 °C intervals, from 100 to 200 °C. The resulting extracts were analyzed using high‐performance liquid chromatography‐mass spectrometry and assayed to determine their inhibitory effect on pancreatic lipase activity in vitro. Four theaflavins (TF), 5 catechins, 2 quercetin glycosides, quinic acid, gallic acid, and caffeine were identified. The total polyphenol content of extracts increased with increasing temperature but lipase inhibitors (TF, theaflavin 3‐O‐gallate, theaflavin 3′‐O‐gallate, theaflavin 3,3′‐O‐gallate, epigallocatechin gallate, and epicatechin gallate) decreased over 150 °C. All extracts inhibited pancreatic lipase but extracts obtained at 100 to 140 °C showed the greatest lipase inhibition (IC₅₀s of 0.9 to 1.3 μg/mL), consistent with the optimal extraction of TFs and catechins except catechin by HCW between 130 and 150 °C. HCW can be used to extract pancreatic lipase‐inhibiting polyphenols from black tea waste. These extracts have potential uses, as dietary supplements and medications, for the prevention and treatment of obesity. Practical Application: Active forms of lipase inhibitors can be recovered from black tea residues. They could be used as dietary supplements or medications.