Compatibility between several heat resistant alloys and sintered Li2O in static helium gas environment

The reaction of sintered Li₂O discs with several commercial heat resistant alloys has been investigated under the conditions of 3.3 × 10⁴Pa ($\text{1}\text{3}\text{atm}$) static He gas atmosphere in the temperature range of 500 and 750° C. Reaction products were identified by X-ray diffraction analysis to be two phases of Li₅FeO₄ and LiCrO₂. The former was dominant below 650° C and the latter was dominant above 650° C. The activation energies of the reaction were determined by the Arrhenius plots for weight changes and sub-scale thickness measurements. The reactivity of the four Fe-Ni-Cr alloys decreased according to the order of Incoloy 800, 316 SS, Hastelloy X-R and Inconel 600. Grain boundary penetration was observed above 500° C for Incoloy 800, 550° C for 316 SS and 600° C for Inconel 600. There was no grain boundary penetration in Hastelloy X-R.     

Three-Phase Static Power Supplies for Air-Conditioned Electric Coaches using High Power GTO

The electrical design, characteristics, construction, and test results of a 170-kVA static power supply using 2500-V 600-A gate turn-off (GTO) thyristors developed for a wide range of electric railway applications are discussed. This power supply is principally composed of a thyristor chopper at an elementary frequency of 360 Hz and three-phase gate turn-off thyristor inverters in the form of a twelve-phase bridge configuration. It is capable of stabilizing a 60-Hz ac voltage and twelve-phase waveform. The bulk and weight of this power supply are ascribed to the avoidance of an inverter commutating circuit, which contains parasitic thyristors, capacitors, and inductances. The applied strategy is derived from the trend of the state of the art regarding switching cells and commuter trains.     

Development of a method to lower recontamination after chemical decontamination by depositing Pt nano particles: (I) Consideration of the suppression mechanism using a quantum dynamics calculation

The Pt coating (Pt-C) process has been developed to lower the recontamination by radioactive elements after chemical decontamination of piping surfaces. In this process, a layer of fine Pt nano particles is formed in an aqueous solution on the base metal of the piping following the chemical decontamination. In this study, we confirmed that the suppression effect by the Pt-C toward ⁶⁰Co deposition on type 316 stainless steel using a ⁶⁰Co deposition test under hydrogen water chemistry. Furthermore, we investigated the suppression mechanism of deposition of radioactive elements by a quantum molecular simulation. The deposition amounts of ⁶⁰Co which were incorporated in oxides after 1000 h with and without the Pt-C process were about 90 and 10.2 Bq/cm², respectively. The amount of ⁶⁰Co deposition with Pt-C is about 10% that of non-coated specimens. The ⁶⁰Co incorporation for the Pt-C specimen was suppressed by decreasing the formation of oxides. We considered this phenomenon using a quantum dynamics calculation and concluded that the Fe–O bonds in oxides were weakened by the effect of Pt and hydrogen radicals which were produced in the reaction between H₂ and Pt, and then oxides were dissolved into the water.     

Analytical method for beta-amyloid fibrils using CE-laser induced fluorescence and its application to screening for inhibitors of beta-amyloid protein aggregation

More than 20 million people are suffering from Alzheimer's disease, and the number of patients will dramatically increase with the arrival of an aging society unless preventive or curative medications are discovered. A fast and sensitive analytical method for beta-amyloid (Abeta) aggregates was developed by the combination of CE-laser induced fluorescence and the fluorescence reagent, thioflavine T. The developed method separates two different fibrils within 5 min. The first peak, which migrated at approximately 4 min, was supposed to be derived from a precursor of a fibril that migrated at approximately 3.5 min. The developed method was also applicable to the high-throughput screening of the Abeta aggregation inhibitors, which was expected to be an effective therapeutic agent candidate of Alzheimer's disease. Three compounds (daunomycin, 3-indolepropionic acid (3-IPA), melatonin) were used for the assay. The order of the antiaggregation activity of these compounds was daunomycin > 3-IPA > melatonin, which was the same as that of the reported one. These results suggest that this analytical method may be used to analyze the Abeta fibrils and identify potential therapeutic agents for the treatment of Alzheimer's disease.     

Augmenting Edge-Connectivity between Vertex Subsets

Given a directed or undirected graph G=(V,E), a collection ${\mathcal{R}}=\{(S_{i},T_{i}) \mid i=1,2,\ldots,|{\mathcal{R}}|, S_{i},T_{i} \subseteq V, S_{i} \cap T_{i} =\emptyset\}$ of two disjoint subsets of V, and a requirement function $r: {\mathcal{R}} \to\mathbb{R}_{+}$ , we consider the problem (called area-to-area edge-connectivity augmentation problem) of augmenting G by a smallest number of new edges so that the resulting graph $\hat{G}$ satisfies $d_{\hat{G}}(X)\geq r(S,T)$ for all X?V, $(S,T) \in{\mathcal{R}}$ with S?X?V?T, where d _G (X) denotes the degree of a vertex set X in G. This problem can be regarded as a natural generalization of the global, local, and node-to-area edge-connectivity augmentation problems. In this paper, we show that there exists a constant c such that the problem is inapproximable within a ratio of $c\log{|{\mathcal{R}}|}$ , unless P=NP, even restricted to the directed global node-to-area edge-connectivity augmentation or undirected local node-to-area edge-connectivity augmentation. We also provide an ${\mathrm{O}}(\log{|{\mathcal{R}}|})$ -approximation algorithm for the area-to-area edge-connectivity augmentation problem, which is a natural extension of Kortsarz and Nutov’s algorithm (Kortsarz and Nutov, J. Comput. Syst. Sci., 74:662–670, 2008). This together with the negative result implies that the problem is ${\varTheta}(\log{|{\mathcal{R}}|})$ -approximable, unless P=NP, which solves open problems for node-to-area edge-connectivity augmentation in Ishii et al. (Algorithmica, 56:413–436, 2010), Ishii and Hagiwara (Discrete Appl. Math., 154:2307–2329, 2006), Miwa and Ito (J. Oper. Res. Soc. Jpn., 47:224–243, 2004). Furthermore, we characterize the node-to-area and area-to-area edge-connectivity augmentation problems as the augmentation problems with modulotone and k-modulotone functions.     

Enhanced Infrared Absorption of C60 on Thin Evaporated Pd Island Films

Infrared transmission spectra of C₆₀ multilayers on thin Pd films deposited onto surface-oxidized Si(100) and hydrogen-terminated Si(111) substrates are reported. In both cases, the spectra in the 1500–1100 cm⁻¹ region exhibited bands at 1444, 1429, and 1182 cm⁻¹ due, respectively, to the A_g (2), T_1u (4), and T_1u (3) modes. The appearance of the A_g (2) mode, which is originally infrared inactive (Raman active), reveals electron transfer from the metal to chemisorbed C₆₀. Indeed, increasing the thickness of C₆₀, the A_g (2) mode intensity saturated more rapidly than the T_1u (4) and T_1u (3) modes. The originally infrared active T_1u (4) and T_1u (3) modes were enhanced in intensity depending upon the Pd thickness. Actually, while both substrates gave nearly the same magnitude of enhancement, the optimum Pd thickness was smaller on the hydrogen-terminated surface than on the surface-oxidized surface. On the other hand, the A_g (2) mode was less intense on the hydrogen-terminated surface than on the oxidized surface, suggestive of a shortage of chemisorbed C₆₀ and thus pointing out the importance of the metal film morphology. Indeed, Pd films deposited on the two substrates gave rise to quite different AFM images. We also show that, regardless of the substrate, the A_g (2) mode is an order of magnitude smaller than for Ag deposition, though no remarkable intensity differences were observed with respect to the T_1u (4) and T_1u (3) modes.     

Microstructure of TiO2 and ZnO Films Fabricated by the Sol-Gel Method

Titanium dioxide and zinc oxide films were fabricated by spin-on and dip-coating methods. Both types of films exhibited columnar grains when the single coating was thin, ∼10 nm. The columnar TiO₂ films were dense, as confirmed by their density values calculated from the refractive index and TEM results. The addition of Al cations into the ZnO suppressed grain growth, because Zn had a lower diffusivity in the doped films. The doped ZnO films had nearly the same electrical resistivity as that of the undoped films.     

Introduction of subsidisation in nascent climate-friendly learning technologies and evaluation of its effectiveness

Given its importance as a practical phenomenon underlying the progress of learning technologies, attention should be paid to the role of subsidisation in learning theory, particularly in the case of nascent climate-related sociable learning technologies, in order to examine its benefits. Thus, this study focuses on subsidy procurement of energy technologies in several economies in the context of the component learning track in endogenous global clusters in order to suggest improvements to the adoption mechanism and examine the climate stabilization constraint. At the same time, the study attempts to determine the global progress ratio of the lithium-ion battery in order to analyse various endogenous learning scenarios for hybrid technologies. An integrated energy system model with highly disaggregated global regions (DNE21+) is used to execute this research in a medium time frame. Subsidisation of the learning track of battery technology encourages greater development of plug-in hybrid vehicles, promotes early diffusion of hybrid technologies, and relieves heavy dependency on crude oil and biofuels. The subsidies in the common learning domains in few economies benefit the nearby economies because of the technology spillover that occurs through numerous cross-feedback learning mechanisms. Endogenous learning with subsidies augments diffusion potentials, abates emissions, and shifts sectoral emissions.     

Alpha-trifluoromethylated carbanion synthons

Trifluomethylated organic compounds often have properties that make them suitable for diverse applications, including materials science, agrochemistry, and pharmaceutical industry. But of all the therapeutic drugs currently available, about 10% of them have a partially fluorinated moiety. Thus, a great deal of attention is being paid to the development of reliable methodologies for trifluoromethylation. Introduction of a trifluoromethyl group into the target molecules mostly relies on either trifluoromethylating reagents or trifluoromethylated synthetic blocks. The chemistry of trifluoromethyl carbanions, nucleophilic trifluoromethylating agents such as the Ruppert-Prakash reagent, and organometallic species has been intensively developed for their important synthetic applications. But the chemistry of beta,beta,beta-trifluoroethyl carbanions (alpha-trifluoromethyl carbanions) and organometallic species has remained undeveloped despite their potential usefulness in organic synthesis. The issue needs to be addressed. This Account outlines successful alkylations and useful synthetic applications of alpha-trifluoromethyl carbanions, such as alpha-substituted beta,beta,beta-trifluoroethyl, alpha-trifluoromethylethenyl, trifluoroacetimidoyl, alpha-trifluoromethyloxiranyl, and related alpha-trifluoromethylated carbanions. The strong electron-withdrawing effect of the alpha-trifluoromethyl group may stabilize the carbanion species electronically. But alpha-trifluoromethyl carbanions and their corresponding organometallic species mostly release fluoride spontaneously to produce difluoroalkenes. This notorious decomposition of alpha-trifluoromethylated carbanions and anionoids has hindered the development of these species for organic synthesis. A well-designed device for the generation, stabilization, and acceleration for alkylation of the alpha-trifluoromethylated carbanions is needed for their synthetic application, as well as stabilization by the electron-withdrawing alpha-substituent. The reported alpha-substituted alpha-trifluoromethyl carbanions can be roughly categorized into three classes based on their structures. The first category, A, is pi-conjugation-stabilized carbanions, which are stabilized by ester, nitro, sulfone, carbonyl, or phenyl groups. alpha-Substituents of these carbanions can delocalize the negative charges on their pi-system with large sigma R electron-withdrawing effects; this prevents accumulation of negative charge on the fluorine atoms. The second category, B, consists of carbanions with sp(3) orbitals either of highly halogenated carbanionsexamples include pentafluoroethyl(trimethyl)fluorosilicate, pentafluoroethyllithium, and alpha,alpha-dichloro-beta,beta,beta-trifluoroethylzinc speciesor of cyclic structures such as oxiranyl- and aziridinyllithiums. Both of these carbanions are also stabilized since they reduce molecular orbital (MO) overlapping of the carbanion orbital to C-F bond orbitals. The third category, C, has carbanions with their anion center at the sp(2) orbital, such as alpha-trifluoromethylated alkenyl carbanions and imidoyl carbanions. These sp(2) orbitals of the carbanion center usually have a small overlap with the C-F bonds of trifluoromethyl groups. The small overlap is able to suppress the E2-type eliminations. alpha-Trifluoromethylated carbanions are, in general, unstable. Their stability is largely affected by factors like hybridization of the orbital that accommodates lone pair electrons, the electronic nature of the alpha-substituents, the degree of covalency in a bond between the carbon and metal, the class of countercation, stabilization by chelation of a metal cation, and so on. The stability, therefore, can be sometimes controlled by tuning these factors adequately so that they can be used for organic synthesis. The chemistry of alpha-trifluoromethylated carbanions for organic synthesis has been progressing steadily. However, the simplest trifluoroethyl and trifluoroacetyl carbanions have never been successfully produced and employed for organic synthesis. Elegant generation and synthetic application of these metal species are one of the most attractive and challenging subjects for active investigation in the future.