Self-healing ability of fly ash–cement systems

Concrete is susceptible to cracking due to both autogenous and drying shrinkage. Nevertheless, most of these types of cracks occur before 28 days. Because fly ash continues to hydrate after 28 days, it is likely that hydrated products from fly ash may modify microstructure, seal these cracks, and prolong the service life. This research investigates the self-healing ability of fly ash–cement paste. Compressive strength, porosity, chloride diffusion coefficients, hydration reactions and hydrated products were studied. The research focuses on behavior after 28 days. According to the experimental results, the fly ash–cement system has the self-healing ability for cracks that occur from shrinkage. The self-healing ability increased when the fraction of fly ash increased.     

Temperature dependence of hydrogen adsorption properties of nickel-doped mesoporous silica

The temperature dependence of the hydrogen adsorption properties of nickel-doped mesoporous silica (MCM-41) synthesized by a direct hydrothermal method was investigated by measuring the amount of hydrogen adsorbed at pressures up to 100 kPa at 298, 373, and 473 K. Nickel-doped MCM-41 adsorbed more hydrogen than undoped MCM-41 and metallic nickel at ≈298/0, 373/0, and 473 K/0 kPa due to chemical adsorption enhanced by the highly dispersed nickel particles. Chemical adsorption increased with increasing nickel content and adsorption temperature, suggesting the presence of adsorption sites. The nickel doping also brought the spillover effect, which enhances the physical adsorption of hydrogen. The spillover effect was enhanced at high nickel contents and adsorption temperatures.     

一种尼泊尔传统豆荚发酵食品Masyaura的感官、生化与营养特征(英文)

Masyaura是尼泊尔出产的一种以豆荚为原料的发酵食品,可以采用传统日光自然干燥以及控制发酵、机械干燥的方法生产,通过感官、生化和营养特征进行评价。结果表明采用控制发酵、机械干燥方式生产的Masyaura,质地脆,密度低,感官评价优于自然发酵的产品。对2种方式生产的产品进行了蛋白质和淀粉的体外消化试验,在自然干燥或控制发酵、机械干燥的Masyaura中,含硫氨基酸都是第一限制性氨基酸。     

Analytical study on the interface of polymer blends from advanced COPNA-resin and nylon 6

In the previous work, we introduced new polymer blends from the advanced COPNA-resin and nylon 6.¹ The morphology of the polymer blends were quite different between the B-staged state and the fully cured state. In order to investigate a phenomenon occurred in the curing process, ¹³C Fourier transform-nuclear magnetic resonance (FT-NMR) spectral analysis, ¹⁵N FT-NMR spectral analysis, and Fourier transform infrared absorptional spectral analysis were carried out on the blends in a solid state. From the spectral analyses, it was revealed that a graft reaction occurred at the interface between the advanced COPNA-resin and the nylon 6. The difference of the morphology on the fully cured polymer blends was due to the following reason. In the curing process, generated benzyl-type cations of the B-staged Advanced COPNA-Resin initially attacked and combined with nitrogen in the amino groups of the nylon 6. In the late stage of the curing process, the cations mainly attacked and combined with π electrons of the condensed aromatics. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 549–557, 1997     

Expression of osteopontin in Meckel's cartilage cells during phenotypic transdifferentiation in vitro, as detected by in situ hybridization and immunocytochemical analysis

The localization of osteopontin (OP) was examined in Meckel's cartilage cells that bipotentially expressed cartilage and bone phenotypes during cellular transformation in vitro. Cultured cells were analyzed by in situ hybridization, immunostaining followed by light and electron microscopy, electron microscopy, and electron probe microanalysis. The combination of ultrastructural analysis and immunoperoxidase staining indicated that OP-synthesizing cells were cells that were autonomously undergoing a change from chondrocytes to bone-forming cells at the top of nodules. Double immunofluorescence staining of 2-week-old cultures revealed that OP was first synthesized by chondrocytic cells at the top of nodules. After further time in culture, the distribution of OP expanded from the central toward the peripheral regions of the nodules. Electron probe microanalysis revealed that the localization of OP was associated with matrices of calcified cartilage and osteoid nodules that contained calcium and phosphorus. Immunoperoxidase electron microscopy revealed that, in addition to the intracellular immunoreactivity in chondrocytes and small round cells that were undergoing transformation, matrix foci of calcospherites and matrix vesicles, in particular, included growing crystals that were immunopositive for OP. An intense signal due to mRNA for OP in 3-week-old cultures was detected in nodule-forming round cells, while fibroblastic cells, spreading in a monolayer over the periphery of nodules, were only weakly labeled. These findings indicate that OP might be expressed sequentially by chondrocytes and by cells that are transdifferentiating further and exhibit an osteocytic phenotype, and moreover, that expression of OP is closely associated with calcifying foci in the extracellular matrix.     

Electrokinetic potential of hydrated cement in relation to adsorption of chlorides

In this study, surface charge mechanism of cement hydrates and its relations to adsorption of chloride ions are investigated. Hydrated cement paste (HCP) shows net positive surface charge by dissociation and adsorption. In HCP, chlorides bind as Friedel's salt (chemical binding) as well as adsorb on the surface of hydrates (physical binding). A surface complexation model is used to predict the adsorption of chlorides on calcium silicate hydrates (C-S-H). A good agreement between experimental and predicted chloride adsorption isotherm clearly demonstrate that the chlorides adsorb on the surface of C-S-H and bringing additional negative surface charge (SiOHCl⁻). However, chloride ions neutralize the positively charged surfaces of portlandite and Friedel's salt by physical adsorption. From the results, it can be concluded that C-S-H is the dominant phase in terms of chloride adsorption in HCP.     

A study on the discovery of relevant fuzzy rules usingpseudobacterial genetic algorithm

This paper presents a new method for the discovery of relevant fuzzy rules using the pseudobacterial genetic algorithm (PBGA). The PBGA was proposed by the authors as a new approach combining a genetic algorithm with a local improvement mechanism inspired by a process in bacterial genetics, named bacterial operation. The presented system aims at the improvement of the quality of the generated fuzzy rules, producing blocks of effective rules and more compact rule bases. This is achieved by encoding the fuzzy rules in the chromosomes in a suitable form in order to make the bacterial operation more effective and by using a crossover operation that adaptively decides the cutting points according to the distribution of degrees of truth values of the rules. In this paper, first, results obtained when using the PBGA for a simple fuzzy modeling problem are presented and compared with other methods. Second, the PBGA is used in the design of a fuzzy logic controller for a semi-active suspension system. The results show the benefits obtained with this approach in both of the studied cases     

Pathogenicity and lethality of a minute intestinal fluke, Neodiplostomum seoulense, to various strains of mice

Atopy is a genetically determined disorder that affects 10%-20% of the population. Many symptoms of patients with atopy (allergic rhinitis, conjunctivitis, asthma, and anaphylaxis) result from events occurring after crosslinking of cell-bound IgE by per se innocuous environmental antigens. The frequently raised hypothesis that autosensitization can also be a pathogenetic factor in atopy, gained support by our recent demonstration of IgE antibodies against human proteins in atopic dermatitis patients. To unravel the molecular nature of IgE-defined autoantigens, we used serum IgE from atopic dermatitis patients to screen a human epithelial cDNA expression library. One of the cDNA-encoding IgE-reactive products contained 1501 bp of a 2274 bp open-reading frame finally identified by sequence analysis of two additional cDNA clones resulting from oligonucleotide screening. The IgE-defined autoantigen, designated Hom s 1, exhibited an almost complete sequence identity with a recently described antigen recognized by cytotoxic T cells of a squamous cell carcinoma patient. Purified recombinant Hom s 1 specifically bound IgE from patients with severe atopy. When used as immunogen in rabbits, recombinant Hom s 1 gave rise to an anti-serum that reacted with a cytoplasmic protein exhibiting a broad cellular and tissue reactivity (skin, lung > gastrointestinal tract > muscle, brain) and identified a 55 kDa protein in blotted serum IgE preparations. The attractive possibility remains that the Hom s 1-triggered IgE response contributes to the events resulting in allergic tissue inflammation. If so, the respective recombinant molecule may serve as a paradigmatic tool for the diagnosis and treatment of patients with "intrinsic" atopy.     

Thermochromism of vanadium–titanium oxide prepared from peroxovanadate and peroxotitanate

Vanadium–titanium complex oxides were prepared through a new synthetic route from peroxovanadate and peroxotitanate solutions, and their thermochromism were investigated. Reflectance spectra for V_0.48Ti_0.52O₂ pellet showed a reversible reflectivity increase in the wavelength region of 700–1,000 nm above 45 °C. The reflectivity was increased gradually from 45 °C to ca. 80 °C unlike the conventional VO₂ which shows an abrupt increase at 67 °C. The mechanism was discussed using powder XRD patterns, SEM images and element distribution maps.