Dissolution Rate of Silicon Nitride Ceramics into Molten CaO–Al2O3–SiO2 Slags

The dissolution rates of silicon nitride (Si₃N₄) ceramics into CaOAl₂O₃SiO₂ slags were investigated by using a rotating specimen method in the temperature range of 1773–1873 K. Dissolution rates in the present study increased as the revolution speed and temperature increased and decreased as the SiO₂ content of the slags increased. The nitrogen content of the slags increased after the Si₃N₄ ceramics had been immersed into them. The slags contained two types of nitrogen ions—N³⁻ and CN^-—because a graphite crucible was used for the experiment. N³⁻ ions were confirmed in all the slags that were used in the present work; the CN^- content was much lower than that of the N³⁻ ions, except in the slag without SiO₂. Based on those results, Ficks law of diffusion was used to analyze the dissolution rates. The dissolution mechanism of the Si₃N₄ ceramics into CaO–Al₂O₃SiO₂ slags has been discussed in this paper.     

Synthesis of 0.4Pb(Mg1/3Nb2/3)O3–0.3Pb(Mg1/2W1/2)O3–0.3PbTiO3 Ceramics by Metal Alkoxide Method, and Its Dielectric Properties

0.4Pb(Mg_1/3Nb_2/3)O₃–0.3Pb(Mg_1/2W_1/2)O₃–0.3PbTiO₃+ x MgO ( x = 0 to 0.04) were prepared by a metal alkoxide method. The percent of perovskite phase of the calcined powders increased with increased calcination temperatures. About 89% of perovskite phase was obtained at 1050°C. The dielectric constant of the pellets fired at 1100°C was increased by the addition of 10 wt% excess Mg(OC₂H₅)₂ and had a maximum value of 7532 at 1 kHz.     

Synthesis of terpolymers having a phospholipid polar group and poly(oxyethylene) in the side chain and their protein adsorption–resistance properties

Terpolymers having phospholipid polar groups were synthesized from 2‐methacryloyloxyethyl phosphorylcholine (MPC), methacryloyl or acryloyl poly(oxyethylene) macromonomers (POEM) [(CH₂CH₂O)_n (where n = 2–23); PEOM(2), PEOM(23), ME(9), Ph(6)], and n‐butyl methacrylate (BMA). The characteristics of these terpolymer membranes were investigated by water content (H) and X‐ray photoelectron spectroscopy. The content of water in the terpolymer increased with increasing content of MPC and length of oxyethylene units. The membranes of terpolymers were found to adsorb bovine serum albumin much less than those of poly(methyl methacrylate) and poly(BMA). Even though the contents of MPC in the terpolymer were 5 to 25 mol %, the terpolymer depressed BSA adsorption more than poly(MPC‐co‐BMA) consisting of 29 mol % of MPC. The use of terpolymer with POEM can decrease the amount of MPC in the polymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1092–1105, 2002     

Morphological Study of Cavity and Worthington Jet Formations for Newtonian and Non-Newtonian Liquids

In this article a morphological study of the cavity formation and the liquid column formation of the Worthington jet with lapse of time for the Newtonian liquids of water and glycerine wt 70% solution and for non-Newtonian liquids of acrylic copolymer solution of ACA-wt1%, ACA-wt2%, and ACA-wt3% by a droplet falling to the free surface of the target liquid in the cylindrical container from a height of H = 100, 200, 300, 400, and 500 mm is described. The calculated results by the energy equation for the maximum cavity radius Rmax/d and for the morphological size D · h/d² of the Worthington jet are in agreement with the experimental results. In order to take photographs of the cavity formation and the Worthington jet formation with lapse of time, a CCD camera was used. The falling droplet and the target liquid are the same material. Here d is the mean diameter of the droplet and D and h are the mean diameter and maximum height of the liquid column of the Worthington jet.     

Experimental Study on Moment–Plastic Rotation Capacity of Hybrid Beams

The moment–inelastic rotation behavior of hybrid steel girder bridges is experimentally investigated. Six welded girders having compact flanges and webs are statically loaded under three-point bending condition in order to simulate the interior pier section of a two-span continuous girder. Six girders, three with hybrid sections and three with homogeneous sections, are designed with three types of web slenderness ratios, resulting in three pairs of hybrid and homogeneous girders. The inelastic rotation capacities obtained from the experimental tests are then compared between hybrid and homogeneous girders. In addition, the results are compared with the prediction moment–inelastic rotation curve proposed in 1998 by White and Barth. It is concluded that, under the condition in this study, hybrid girders have more deformation capacity than homogeneous girders, and that the prediction curve is more conservative for a specimen with higher web slenderness ratio.     

A cyber attack-resilient server inspired by biological diversity

This paper describes a novel cyber attack-resilient server inspired by the concept of biological diversity. The server consists of several virtual machines running different operating systems and different implementations of the same server protocol specification. This approach is based on the observation that not all implementations are affected by the same vulnerability, except for vulnerabilities in specifications and on shared libraries. A prototype system was built and tested to evaluate the continuity of the service. The results showed that, by exploiting a vulnerability, the prototype system could suppress downtime of the DNS service to less than 4 s without false positives.     

Reduction of haematite to magnetite under controlled hydrothermal conditions with hydrogen gas

Haematite (-Fe₂O₃) was reduced to magnetite (Fe₃O₄) under hydrothermal conditions, by the use of an autoclave into which hydrogen gas was able to be admitted. The stable reduced conditions for magnetite precipitation were produced even at 100 °C. In acid and neutral mineralizers, the rate of haematite reduction was small below 300 °C and increased with an increase in reaction temperature above 300 °C. Magnetite crystals obtained in these solutions were large and faceted octahedrons in shape. Alkaline mineralizers except NaOH solution accelerated the reduction at low temperatures below 300 °C and gave small magnetite crystals. The reduction of haematite to magnetite was completed even at 150 °C in concentrated CsOH solution (1.0 mol l^–1).     

Design,Synthesis, and Biological Evaluation of Novel Fluorescent Probes Targeting the 18-kDa Translocator Protein

A series of fluorescent probes from the 6-chloro-2-phenylimidazo[1,2-a]pyridine-3-yl acetamides ligands featuring the 7-nitro-2-oxa-1,3-diazol-4-yl (NBD) moiety has been synthesized and biologically evaluated for their fluorescence properties and for their binding affinity to the 18-kDa translocator protein (TSPO). Spectroscopic studies including UV/Vis absorption and fluorescence measurements showed that the synthesized fluorescent probes exhibit favorable spectroscopic properties, especially in nonpolar environments. In vitro fluorescence staining in brain sections from lipopolysaccharide (LPS)-injected mice revealed partial colocalization of the probes with the TSPO. The TSPO binding affinity of the probes was measured on crude mitochondrial fractions separated from rat brain homogenates in a [¹¹C]PK11195 radioligand binding assay. All the new fluorescent probes demonstrated moderate to high binding affinity to the TSPO, with affinity (K_i) values ranging from 0.58 nM to 3.28 μM. Taking these data together, we propose that the new fluorescent probes could be used to visualize the TSPO.     

Homoepitaxial diamond p–n+ junction with low specific on-resistance and ideal built-in potential

We have realized low specific on-resistance and ideal built-in potential simultaneously for a (111)-oriented homoepitaxial diamond p–n⁺ junction. As the p–n⁺ junction, the heavily phosphorus doped n⁺-type layer, which shows variable range hopping conduction, was formed on the (111)-oriented boron doped p-type one. By using this hopping conduction, the resistivity of the n⁺-type layer becomes lower by three orders of magnitude than that of a lightly P-doped layer. Current density–voltage characteristics showed a rectification ratio of 10⁶ at ± 15 V at room temperature. The current density and the specific on-resistance at forward bias voltage of 15 V at room temperature are over 100 A/cm² and 8 × 10^− 2 Ωcm², respectively. This low specific on-resistance corresponds to the lower resistivity of the n⁺-type layer by three orders of magnitude than that of conventional lightly P-doped n-type layer. The existence of the space-charge layer at the vicinity of the p–n⁺ junction was confirmed from capacitance–voltage (C–V) characteristics. From C⁻²–V characteristics at 200 °C, the built-in potential was estimated as approximately 4.4 eV, which is identical to that of conventional diamond p–n junction.