Activities of FexO in CaO + CaF2 + SiO2 + FexO quaternary slags by disposable electrochemical oxygen probes

The activities of Fe_xO in CaO + CaF₂ + SiO₂ + Fe_xO quaternary slags were measured by means of solid-oxide galvanic cell. The Fe_xO activities in the slags are influenced by CaF₂ as well as SiO₂. At constant Fe_xO mole fractions, e.g., , at low SiO₂ mole fractions i.e., , the substitution of CaF₂ for CaO has an effect of raising the Fe_xO activity. At higher SiO₂ mole fractions, e.g., , however, such an effect becomes insignificant.     

Thermal Diffusion of Si Atoms at the Interface of Mo／Si Bilayers Studied with a Soft X-ray Emission Microscope

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Residual stress versus microstructural effects on the strength and toughness of phase-separated PbO–B2O3–Al2O3 glasses

A few authors have reasonably proposed that liquid–liquid phase-separated (LLPS) glasses could show improved fracture strength, S_f, and toughness, K_Ic, as the second phase could provide a barrier to crack propagation via deflection, bowing, trapping, or bridging. Due to the associated tensile or compressive residual stresses, the second phase could also act as a toughening or a weakening mechanism. In this work, we investigated five glasses of the PbO–B₂O₃–Al₂O₃ system spanning across the miscibility gap: Four of them undergo LLPS—three are binodal (two B₂O₃-rich and one PbO-rich) and one is spinodal—and one does not show LLPS (composition outside the miscibility gap). Their compositions were designed in such a way that the amorphous particles are under compressive residual stresses in some and under tensile residual stresses in others. The following mechanical properties were determined: the Vickers hardness, ball on three balls (B3B) strength, and toughness, K_Ic-SEVNB (single-edge V-notch beam [SEVNB]). The microstructures and compositions were analyzed using scanning electron microscopy with energy-dispersive X-ray spectrometry. The spinodal glass showed, by far, the best mechanical properties. Its K_Ic-SEVNB = 1.6 ± 0.1 MPa m^1/2, which embodies an increase of almost 50% over the B₂O₃-rich binodal composition, and 90% considering the PbO-rich binodal composition. Moreover, its fracture strength, S_f = 166 ± 7 MPa, is one of the highest ones ever reported for an LLPS glass. Fracture analyses evidenced that the spinodal composition exhibited the lowest net stress at the fracture point. Moreover, calculations indicate that the internal residual stress level is the lowest in the spinodal glass. The overall results indicate that the microstructural effect of the spinodal glass is the most significant factor for its superior mechanical properties. This work corroborates the idea that LLPS provides a feasible and stimulating solution to improve the mechanical properties of glasses.     

Aluminium oxide grafted on silica gel surface: Study of the thermal stability, structure and surface acidity

The synthesis of aluminium oxide grafted on silica gel surface was carried out by the reaction of a suitable aluminium precursor with the surface hydroxyl groups, SiOH, of the oxide support in non-aqueous solvent. The advantage of this preparation method, compared to the conventional ones (impregnation or precipitation and calcination), is that the oxide is highly dispersed on the surface (monolayer or submonolayer). The resulting material, SiO₂/Al₂O₃, was heat treated at temperature range of 423 to 1573 K. The Al/Si atomic ratios, determined by X-ray photoelectron spectroscopy (XPS), showed that aluminium is less mobile up to heat treatment of 1173 K and above this temperature part of it diffuses to the interior of the matrix. ²⁷Al solid state nuclear magnetic resonance spectroscopy (NMR) showed two different environments, tetrahedral and octahedral for sample calcined up to 1023 K and above this temperature, aluminium in a trigonal bipyramidal environment was also detected. Pyridine adsorbed on a Lewis acid sites were observed for samples calcined up to 1023 K, and above this temperature they were not detected.     

Minichromosome formation in Chlorella cells irradiated with electron beams

Three minichromosomes, miniP7, miniB7, and miniK4 of 800 kbp, 450 kbp, and 550 kbp, respectively, were obtained from Chlorella vulgaris chromosome I by electron-beam irradiation. Two of them were structurally characterized: MiniP7 was formed by the deletion of an internal 180 kbp close to the right end of chromosome I. The 180-kbp region with a small interspersed nuclear element (SINE)-like element on its left terminus was translocated to another chromosome, leaving a footprint-like structure on miniP7. MiniB7 was a hybrid of chromosome I and another chromosome, retaining the left telomere and the centromere of chromosome I. The centromeric repetitive elements served as a rearrangement point in the miniB7 formation. These examples showed the complicated mechanisms involved in the minichromosome formation. The minichromosomes thus obtained can be useful for isolating the fundamental structural elements of a chromosome. Moreover, they may serve as starting materials or a vector to generate artificial chromosomes carrying useful genes.     

Developing a long-term local society design methodology towards a low-carbon economy: An application to Shiga Prefecture in Japan

To tackle global climate stabilization concretely, we have developed a method formulating long-term scenarios towards a low-carbon economy at local level. As a result of the pioneering application of this method to Shiga Prefecture, we have found the following: (i) it is possible to design scenarios for moving towards a low-carbon economy in which CO₂ emission is lowered by 30–50% from the 1990 level by 2030, while the prefecture's gross production continues to grow by 1.6% annually; (ii) in order to halve the emission by 2030, socio-economic structural changes as well as technological measures are essential; and (iii) innovative measures at the prefectural level, such as land planning, renewable energy promotion and lifestyle change, play an increasingly important role as the target reduction rate gets higher.     

Quantitative three-dimensional characterization of pearlite spheroidization

We investigated the pearlite spheroidization of a 0.8 mass% C–Fe steel under 700 °C static annealing conditions using a combination of computer-aided three-dimensional (3-D) tomography and electron back-scattered diffraction. The holes present in naturally grown cementite lamellae cause shape instability and induce shape evolution of the lamellar structure during spheroidization. 3-D visualization demonstrated that the intrinsic holes play an important role in the initiation and development of pearlite spheroidization. The hole coalescence and expansion causes the break-up up of large cementite lamellae into several long narrow ribbons. Furthermore, the growth mechanism of inter-hole coalescence is related to the ratio of half the inter-hole distance on a cementite lamella to the thickness of that lamella. The driving force for hole growth is either the difference in surface energy or the curvature between the hole edges and the adjacent flat surface of the lamella. The morphologies of cementite ribbons depend on the hole expansion position on cementite lamella, and can change their shape to cylinders or small spheres by Rayleigh’s perturbation process after prolonged spheroidization.     

Vapor phase photografting of methyl methacrylate on polymer films: Accelerating effects of solvent mixed with monomer

The effects of solvent mixed with monomer on benzopheneone-sensitized photografting of methyl methacrylate on polymer films were investigated in vapor phase at 60°C. The grafting on nylon 6 film was promoted by adding a pertinent quantity of solvent, such as phenol, m-cresol, benzyl alcohol, and formic acid, to the monomer. The similar effects accelerating the grafting on polyester film were observed for solvent, such as m-cresol, phenol, o-chlorophenol, and nitrobenzene. Such an accelerating function of the solvents is supposed to originate in the swelling of the film substrates due to solvents. On the other hand, solvents such as n-decane, decalin, and p-xylene retarded the grafting on low density polyethylene and polypropylene films. The differences in the solvent effects by the types of film substrates are discussed in terms of photoinduced radicals on the substrates containing solvents.