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A large-scale demonstration test of a triaxial high-temperature superconducting (HTS) cable for a practical cable system was performed in a chemical plant of a private company. The 200 m-long HTS (REBCO: REBa2Cu3O7-δ) triaxial cable, which was manufactured by connecting 3 cables using 2 joints via a snake-shaped layout, was laid approximately 5 m higher than ground level, and the cable was cryocooled by circulating liquid nitrogen. For the preverification test, the rise-up test of the liquid nitrogen and the development of technology for bending the cable, joining it, as well as laying and installing it, were conducted. No leakage of liquid nitrogen at the terminal due to damage caused by heat shock or liquid nitrogen drop impact was observed. The pressure required for the liquid nitrogen to achieve a 5 m height was from 27.5 to 33 kPa, which is in good agreement with the calculated pressure of 33.6 kPa. The cooling rate was well controlled, and the desired level of 4 K/h was achieved. The economic challenges and methods of achieving market penetration were also discussed. The goal was to realize a superconducting cable for practical applications, and it was thought that the energy and costs necessary for cryocooling could be drastically reduced by using the existing cold system in the plant. In this way, it is expected HTS cables can achieve low costs and high energy-saving effects and penetrate markets in the future.

We investigated the chemical pressure effects on structural and electronic properties of SnTe-based material using partial substitution of Sn by Ag0.5Bi0.5, which results in lattice shrinkage. For Sn1−2x(AgBi)xTe, single-phase polycrystalline samples were obtained with a wide range of x. On the basis of band calculations, we confirmed that the Sn1−2x(AgBi)xTe system is basically possessing band inversion and topologically preserved electronic states. To explore new superconducting phases related to the topological electronic states, we investigated the In-doping effects on structural and superconducting properties for x = 0.33 (AgSnBiTe3). For (AgSnBi)(1−y)/3InyTe, single-phase polycrystalline samples were obtained for y = 0–0.5 by high-pressure synthesis. Superconductivity was observed for y = 0.2–0.5. For y = 0.4, the transition temperature estimated from zero-resistivity state was 2.4 K, and the specific heat investigation confirmed the emergence of bulk superconductivity. Because the presence of band inversion was theoretically predicted, and the parameters obtained from specific heat analyses were comparable to In-doped SnTe, we expect that the (AgSnBi)(1−y)/3InyTe and other (Ag, In, Sn, Bi)Te phases are candidate systems for studying topological superconductivity.

The copper ore in Chilean copper porphyry deposits is often associated with molybdenum minerals. This copper–molybdenum (Cu–Mo) sulfide ore is generally mined from various locations in the mining site, thus, the mineral composition, oxidation degree, mineral particle size, and grade vary. Therefore, in the mining operation, it is common to blend the ores mined from various spots and then process them using flotation. In this study, the floatability of five types of Cu–Mo ores and the blending of these ores in seawater was investigated. The oxidation degree of these Cu–Mo ores was evaluated, and the correlation between flotation recovery and oxidation degree is presented. Furthermore, the flotation kinetics of each Cu–Mo ore were calculated based on a mineralogical analysis using mineral liberation analysis (MLA). A mineralogical prediction model was proposed to estimate the flotation behavior of blended Cu–Mo ore as a function of the flotation behavior of each Cu–Mo ore. The flotation results show that the recovery of copper and molybdenum decreased with the increasing copper oxidization degree. In addition, the recovery of blended ore can be predicted via the flotation rate equation, using the maximum recovery (Rmax) and flotation rate coefficient (k) determined from the flotation rate analysis of each ore before blending. It was found that Rmax and k of the respective minerals slightly decreased with increasing the degree of copper oxidation. Moreover, Rmax varied greatly depending on the mineral species. The total copper and molybdenum recovery were strongly affected by the degree of copper oxidation as the mineral fraction in the ore varied greatly depending upon the degree of oxidation.

OBJECTIVES: Thiamine acts as a coenzyme (prosthetic group) after converting to thiamine pyrophosphate in crucial metabolic enzymes of pyruvate dehydrogenase, α-ketoglutarate dehydrogenase and transketolase. Theoretically, thiamine should not be consumed by an increase in the number of substrates for those enzymes. However, thiamine is often described to be consumed by excessive carbohydrate intake. Such a possible misunderstanding is assessed in the relevant literature. METHODS: The original paper (Elmadfa, et al. Int J Vitam Nutr Res 2001), which seems to mislead the reader into considering an increase in thiamine requirement for excessive carbohydrate intake, and the relevant papers were reviewed. RESULTS: The original paper demonstrated that increases in carbohydrate intake from 55% to 65% and 75% of total energy caused decreases in plasma and urine concentrations of thiamine, while erythrocyte transketolase activity remained unchanged. This seems to misleadingly support the idea that excessive carbohydrate intake increases the thiamine requirement for carbohydrate metabolism. It could be interpreted as the decreases of thiamine concentrations were observed only during an adaptation period. It was reported that diabetic patients had low plasma thiamine levels in association with increased renal clearance and fractional excretion of thiamine, without a decrease in erythrocyte transketolase activity (Thornalley, et al. Diabetologia 2007). As a similar case of possible misinterpretation, a case report (Watson, et al. Ir J Med Sci 1981) demonstrated that glucose loading precipitated thiamine deficiency in malnourished patients with latent thiamine deficiency. CONCLUSIONS: From the relevant literature, it is inferred that excessive carbohydrate intake in people without hyperglycemia could lead to a small increase, if any, in urinary thiamine excretion, but not to an increase in thiamine requirement for glucose metabolism. Even in the academic field, it seems that thiamine is often misunderstood to be consumed by excessive carbohydrate intake. FUNDING SOURCES: None.

Overcoming the slow-leaching kinetics of refractory primary copper sulfides is crucial to secure future copper sources. Here, the effect of carbon was investigated as a catalyst for a bioleaching reaction. First, the mechanism of carbon-assisted bioleaching was elucidated using the model chalcopyrite mineral, under specified low-redox potentials, by considering the concept of Enormal. The carbon catalyst effectively controlled the Eh level in bioleaching liquors, which would otherwise exceed its optimal range (0 ≤ Enormal ≤ 1) due to active regeneration of Fe3+ by microbes. Additionally, Enormal of ~0.3 was shown to maximize the carbon-assisted bioleaching of the model chalcopyrite mineral. Secondly, carbon-assisted bioleaching was tested for three types of chalcopyrite/enargite-bearing complex concentrates. A trend was found that the optimal Eh level for a maximum Cu solubilization increases in response to the decreasing chalcopyrite/enargite ratio in the concentrate: When chalcopyrite dominates over enargite, the optimal Eh was found to satisfy 0 ≤ Enormal ≤ 1. As enargite becomes more abundant than chalcopyrite, the optimal Eh for the greatest Cu dissolution was shifted to higher values. Overall, modifying the Eh level by adjusting AC doses to maximize Cu solubilization from the concentrate of complex mineralogy was shown to be useful.

Sequential treatment was applied to carbonaceous Au-Ag-bearing ore concentrate to maximize the Au and Ag recovery. In the preliminary test, the present carbonaceous ore had well liberated and exposed type of gold grains, which are not refractory, but included mainly three types of Ag presented as electrum, hessite (Ag2Te) and Ag-bearing other minerals. Au recovery was ∼100% without any treatment, meanwhile Ag recovery was only 33.3%. The sequential treatment comprises two oxidation steps: (a) mixed culture of iron- and sulfur-oxidizing microorganisms at pH 1.2, followed by (b) cell-free spent medium (CFSM) at pH 4.0 from a white rot-fungus, Phanerochaete chrysosporium, which includes lignin-degrading enzymes. As a result, Ag recovery was 55.5% after the first step and greatly improved to ∼100%, including the dissolved Ag+ concentration in the first step of acid treatment. Although the acidophilic iron-oxidizing microorganisms were inhibited by dissolved Ag+ and Cd2+ ions, the strong acidic conditions dissolved hessite and Ag-bearing oxide minerals. However, the remaining carbonaceous matter acted to sorb Ag(CN)2− in cyanidation, causing the recovery loss. In the next step the lignin-degrading enzymes degraded carbonaceous matter in the ore. This step is necessary to avoid the adsorption of Ag(CN)2− on graphitic carbonaceous matter, leading a mostly perfect recovery of the remaining Ag in the solid residues, without necessity of alkaline washing. The sequential treatment including enzymatic lignin-degrading process was also effective in carbonaceous silver ore avoiding the emission of air pollutants.

Ce1–xPrxOBiS2 powders and Ce0.5Pr0.5OBiS2 single crystals were synthesized and their structure and superconductive properties were examined by X-ray diffraction, X-ray absorption, electronic resistivity, and magnetization. While PrOBiS2 was found to be in a monoclinic phase with one-dimensional Bi–S zigzag chains showing no superconductive transition above 0.1 K, CeOBiS2 was in a tetragonal phase with two-dimensional Bi–S planes showing zero resistivity below 1.3 K. In the range x = 0.3–0.9 in Ce1–xPrxOBiS2, both monoclinic and tetragonal phases were formed together with zero resistivity up to a maximum temperature of 2.2 K. A Ce0.5Pr0.5OBiS2 single crystal, which showed both zero resistivity and a decrease in magnetization at ∼2.4 K, presented a tetragonal structure. Short Bi–S bonding in flat two-dimensional Bi–S planes and mixed Ce3+/Ce4+ were characteristic features of the Ce0.5Pr0.5OBiS2 single crystal, which presumably triggered its superconductivity.

Nanoparticles of e-Fe2O3 in an amorphous silica matrix were prepared by the sol–gel method without using a precursor. X-ray diffraction patterns reflect a completely amorphous state for the samples even after heat-treated up to 600 °C, while at higher temperatures the formation of crystalline iron oxide phases was observed. Transmission electron microscopy analysis showed a wide size distribution of nanoparticles from 3±0.5 to 46±0.8 nm. The occurrence of e-Fe2O3 particles depends on several factors like annealing temperature, particle size and iron concentration in initial chemicals. Based on the 57Fe Mossbauer spectra, three octahedral and one tetrahedral iron site were identified for e-phase. The optimized conditions for the preparation of e-Fe2O3 rich sample were confirmed and ~ 90% of the e-Fe2O3 phase was obtained with the particle size of 15±0.6 nm. The high coercivity of ~ 1.18 T at room temperature was confirmed for our nanoparticle system.

The effect of sodium sulfite (Na2SO3) on the floatability of chalcopyrite and enargite was investigated in this work. The micro flotation tests of single and mixed minerals were performed under various concentrations of Na2SO3. The micro flotation tests of single minerals showed that Na2SO3 depressed the floatability of both minerals at pH 9 in the absence of potassium amyl xanthate (PAX). Interestingly, the addition of PAX followed by the Na2SO3 treatment selectively improved the recovery of enargite. On the other hand, the recovery of chalcopyrite remained low under a similar condition. The single mineral flotation results indicate that separation of chalcopyrite and enargite might be possible using PAX and Na2SO3 treatment. Indeed, the mixed mineral flotation results were in agreement with the flotation results of single minerals. The mineral surface was analyzed by X-ray photoelectron spectroscopy (XPS) after the treatments to explain the phenomenon. The XPS results show the presence of sulfate species on both mineral surfaces after the Na2SO3 treatment. The adsorbed PAX could prevent the formation of this sulfate species on the enargite surface and rendered the surface hydrophobic. However, the adsorbed PAX could not prevent the formation of sulfate species on the chalcopyrite surface and rendered the surface hydrophilic.

The viscoelastic properties of poly(methyl methacrylate) (PMMA)/grafted poly(butyl acrylate) (PBA) nanoparticle systems were investigated. The rubber particles consist of PBA core (60 nm in diameter) and grafted PMMA shell. The grafting degree, defined as the weight ratio of grafted PMMA to PBA particles, ranges from 0.8 to 1.5. Two series of samples, A series with 7.5 wt.% of PBA content and B series with 12 wt.% of PBA content, were used. The systems exhibited fast and slow relaxation process, the former reflecting the relaxation of the matrix PMMA chains and the latter being attributed to grafted PBA particles. For A series samples, time-temperature superposition (TTS) was held well over the frequency (ω) and temperature (T) ranges measured. However, for B series samples, TTS was not satisfied at low ω due to the particle-particle interaction of grafted PBA particles, although the samples obeyed TTS at high ω associated with the relaxation with entanglement of matrix PMMA. At high T and low ω region, the B series samples showed a sol-gel transition at elevating T and the critical gel behavior characterized with a power-law relationship, G′ = G″/tan(nπ/2) ∝ ωn, was observed. This behavior suggested formation of a self-similar, fractal structure of grafted PBA particles. The critical gel temperature (T gel) and the critical exponent (n) were determined for the B series samples. TEM observations revealed that as-prepared A and B samples had well-dispersed particles but the B samples after viscoelastic measurements had fragmented networks of the PBA particles, confirming that the sol-gel transition occurred for the PMMA/grafted PBA systems at elevating T.

Superconducting transition temperature (Tc) reported in SnAs-based layered compound NaSn$_2$As$_2$ varies from 1.2 to 1.6 K, implying that its superconductivity is critically sensitive to non-stoichiometry. Here, we demonstrate that Na-doping on the Sn site (Na$_{1+x}$Sn$_{2-x}$As$_2$) is effective in enhancing superconductivity, leading to Tc = 2.1 K for x = 0.4. First-principles calculation indicates that such a doping, or Na$_{\rm Sn}$ antisite defects, is energetically favored over other cation vacancies. Our results pave the way for increasing Tc of layered tin pnictide superconductors., 21 pages, 9 figures, 1 Table

Empagliflozin, one of sodium-glucose co-transporter 2 (SGLT2) inhibitors, has been demon- strated to have beneficial effects on cardiovascular morbidity and mortality in patients with type 2 diabetes at high risk for cardiovascular events. The mechanisms behind these benefits of empagliflozin are presumed to include osmotic diuresis, being rather close to water diuresis than sodium diuresis. Two cases are presented here, where distinct changes in urinary water and sodium excretion were seen immediately after replacing tolvaptan, a water diuretic, with empagliflozin. Case 1 with heart failure showed a large decrease in urinary sodium excretion with a slight decrease in urine volume. By contrast, Case 2 with nephrotic syndrome showed a large increase in urinary sodium excretion with an increase in urine volume. The differences were probably due to distinct diuretic effects of empagliflozin and tolvaptan in the presence of sodium diuretics as well as distinct pathological conditions. In addition, the amount of urine protein was reduced after the replacement in Case 2. SGLT2 inhibitors would be expected to have the potential to exert some beneficial effects other than lowering blood glucose levels by increasing urinary glucose excretion.

Effect of oxidation treatment using hydrogen peroxide (H2O2) on the floatability of copper sulfide minerals (i.e., chalcopyrite and bornite) and arsenic-bearing copper minerals (i.e., tennantite and enargite) is reported in this study. Pure mineral flotation shows that the floatability of each mineral significantly decreases after the oxidation treatment. Interestingly, flotation of mixed mineral of copper sulfide and arsenic-bearing copper minerals shows that enargite and tennantite exhibit a higher floatability compared to chalcopyrite and bornite after the oxidation treatment followed by the addition of potassium amyl xanthate (PAX). These flotation results indicate a possibility for selective flotation of copper sulfide and arsenic-bearing copper minerals. Indeed, bench-scale flotation tests show that the oxidation treatment using H2O2 and the addition of PAX can deliver a satisfying separation of copper sulfide and arsenic-bearing copper minerals. Difference oxidation products (i.e., CuO, Cu(OH)2, CuSO4, FeOOH, and Fe2(SO4)3) on each mineral surface are likely the cause of this different flotation behavior. Furthermore, these oxidation products may affect the adsorption amount of PAX on each mineral. Indeed, the adsorption tests show that PAX is adsorbed more on tennantite, bornite, and enargite compared to chalcopyrite owing to the formation of CuSO4 and Cu(OH)2 on the mineral surfaces under oxidizing conditions. A possible mechanism is proposed in this study to explain the selective flotation behavior of mixed minerals.

We have investigated the microdomain structure and viscoelastic properties of polystyrene-block-poly(ethylene-co-(ethylene-propylene)-block-polystyrene copolymer (SEEPS-1)/paraffinic oil (Oil-1) blends. The SAXS results revealed that, with increasing oil content, the structures change from a lammelar microdomain for SEEPS-1/Oil-1 = 100/0 to a hexagonally packed cylindrical microdomain for SEEPS-1/Oil-1 = 75/25 blend, and furthermore change to a spherical microdomain packed in a cubic lattice for SEEPS-1/Oil-1 = 50/50 and 25/75 blends. SEEPS-1/Oil-1 = 100/0 and 75/25 blends held each same microdomain structure below 300 °C. In contrast, SEEPS-1/Oil-1 = 50/50 and 25/75 blends, respectively, exhibited order-disorder transition temperature (T ODT) at 210–220 °C and 150–160 °C. Below T ODT, the microdomain structures did not change. Corresponding to the SAXS observations, the viscoelastic responses showed that the dynamic storage modulus G′, respectively, is proportional to ω1/2, ω1/4∼ω1/3, and ω0 at low frequencies for SEEPS-1/Oil-1 = 100/0, 75/25, and 50/50 and 25/75, indicating lamellar, cylindrical, and spherical microdomains The time-temperature superposition was applicable on the ordered state, and the activation energy obtained from the shift factors was roughly independent of blend composition (in other words, microdomain structure), suggesting that the viscoelastic responses are due to the presence of defects of long range order of microdomain structures.

High-entropy-alloy-type tellurides M-Te, which contain five different metals of M = Ag, In, Cd, Sn, Sb, Pb, and Bi, were synthesized using high pressure synthesis. Structural characterization revealed that all the obtained samples have a cubic NaCl-type structure. Six samples, namely AgCdSnSbPbTe5, AgInSnSbPbTe5, AgCdInSnSbTe5, AgCdSnPbBiTe5, AgCdInPbBiTe5, and AgCdInSnBiTe5 showed superconductivity. The highest transition temperature (Tc) among those samples was 1.4 K for AgInSnSbPbTe5. A sample of AgCdInSbPbTe5 showed a semiconductor-like transport behavior. From the relationship between Tc and lattice constant, it was found that a higher Tc is observed for a telluride with a larger lattice constant., 9 pages, 4 figures

Superconductivity with exotic properties has often been discovered in materials with a layered (two-dimensional) crystal structure. The low dimensionality affects the electronic structure of materials, which could realize a high transition temperature (Tc) and/or unconventional pairing mechanisms. Here, we report the superconductivity in a layered tin arsenide NaSn2As2. The crystal structure consists of (Sn2As2)2- bilayers, which is bound by van-der-Waals forces, separated by Na+ ions. Measurements of electrical resistivity and specific heat confirm the bulk nature of superconductivity of NaSn2As2 with Tc of 1.3 K. Our results propose that the SnAs layers will be a basic structure providing another universality class of a layered superconducting family, and it provides a new platform for the physics and chemistry of low-dimensional superconductors with lone pair electrons., Comment: 12 pages, 1 table, 3 figures

Leukocyte telomere length and serum levels of high-molecular-weight adiponectin and dehydroepiandrosterone-sulfate (DHEA-S) were assessed in association with nutrition and performance status (PS) in Japanese centenarians. Twenty-three centenarians (five men, 18 women) were classified according to their PS 1 (nearly fully ambulatory, n = 2), 2 (in bed less than 50% of daytime, n = 10), 3 (in bed greater than 50%, n = 6), and 4 (completely bedridden, n = 5). Leukocyte telomere length was determined by the hybridization protection assay, and the adiponectin and DHEA-S levels were measured by chemiluminescent enzyme immunoassay. Among variables of PS, body mass index (BMI), albumin, adiponectin, DHEA-S, and telomere length, there were significant correlations between PS and albumin ( r = −.694, p < .01), between telomere length and BMI ( r = .522, p < .05), between adiponectin and BMI ( r = −.574, p < .01), and between DHEA-S and albumin ( r = .530, p < .01). When excluding two cancer-bearing centenarians with short telomere, telomere length significantly correlated with PS ( r = −.632, p < .01). It was indicated that the short leukocyte telomere was associated with poor PS and cancer development and that the adiponectin or DHEA-S was associated with adiposity or nutritional status. Despite a small number of subjects, these biomarkers seemed to reflect distinct aspects of longevity in Japanese centenarians.

Linear viscoelastic properties of carbon black (CB) suspensions with various CB concentrations (cCB) in two suspending media, mixtures of a rosin-modified phenol resin-type varnish (Varnish-1)/an alkyd resin-type varnish (Varnish-2) and Varnish-1/petroleum solvent (AF) were investigated. The former medium has higher affinity and the latter has poorer affinity toward CB particles than Varnishi-1, although these two media have almost the same viscoelastic properties. Both CB/(Varnish-1/Varnish-2 = 60/40) and CB/(Varnish-1/AF = 80/20) suspensions exhibited a sol–gel transition on an increase in cCB, as similar to the behavior of CB/Varnish-1 suspensions. But, for the CB/(Varnish-1/Varnish-2 = 60/40) suspensions the critical gel concentration (cgel) was lower and the critical relaxation exponent (n) was higher than that of CB/Varnish-1 suspensions. In contrast, for the CB/(Varnish-1/AF = 80/20) suspensions cgel and n, respectively, were almost the same value as those of CB/Varnish-1 suspensions. These results strongly suggest that cgel and n are attributable to the medium affinity, but not to the medium viscosity, and the CB fractal structure changes from plane-like to straight-line structure with increasing medium affinity.

HTS current leads have been prepared by the TFA-MOD processed YBCO tapes 5 mm in width and around 120 μm in overall thickness. The YBCO superconducting thin layer with 1.5 μm is formed on the oxide buffer layers deposited on Hastelloy substrate tape. The critical current of the YBCO tapes is around 100 A at 77 K in self-field. A current lead unit is composed of a GFRP board and five YBCO tapes soldered to Cu cap at both ends. The transport current of the ten current lead units ranges from 536 A to 408 A at 77 K in liquid nitrogen. The YBCO current lead is assembled from the ten current lead units in parallel. The transport current of 4,000 A at 77 K was stably carried with no voltage generation on the YBCO tapes of the assembled current lead for ten minutes. Furthermore, the trans port current of 5,000 A was successfully applied with voltage of around 200 μV on YBCO tapes. The heat leakage of the assembled YBCO current lead with 150 mm in length between 77 K and 4.2 K is estimated to be 470 mW. Therefore, the heat load of it at transport current of 4000 A corresponds to 0.12 W/kA, which is one order of magnitude smaller than that of conventional Cu current lead. The small heat load results from high current performance and low thermal conductivity in the present YBCO current lead.

Blend systems of polystyrene-block-poly(ethylene-co-(ethylene-propylene))-block-polystyrene (SEEPS) triblock copolymer with three types of hydrocarbon oil of different molecular weight were prepared. The E″ curves as a function of temperature exhibited two peaks; one peak at low temperature (≅ −50°C), arising from the glass transition of the poly[ethylene-co-(ethylene-propylene)] (PEEP) phase and a high temperature peak (≅ 100°C), arising from the glass transition of the polystyrene (PS) phase. The glass transition temperature (Tg) of the PEEP phase shifted to lower temperature with increasing oil content. The shifted Tg depended on the types of oil and was lower for the low molecular weight oil. The Tg of PS phase of the present blend system, were found to be constant and independent of the oil content, when molecular weight of the oil is high. However, for the lower molecular weight oil, the Tg of the PS phase also shifted to lower temperatures. This fact indicates that the oil of high molecular weight is merely dissolved in the PS phase. The E′ at (75°C, at which temperature both of PEEP and PS phases are in glassy state, was found to be independent of oil content. In contrast, at 25°C, at which temperature the PEEP phase is in rubbery state, the E′ decreased sharply with increasing oil content. This result indicates that the hydrocarbon oil was a selective solvent in the PEEP phase. It mainly dissolved in the PEEP phase, although slightly dissolved into the PS phase as well, when molecular weight of oil is low. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Uniaxial elongational viscosity of SiO2/(acrylic polymer/epoxy (AP/EP)) suspensions with various SiO2 volume fractions (ϕ) in a blend of acrylic polymer and epoxy was investigated at various temperatures (T). The matrix polymer ((AP/EP) blend) contained 70 vol.% of EP. At ϕ ≤ 35 vol.% at T ≤ 80°C, where the suspensions were in sol state, strain-hardening behavior was observed. This strain hardening of the suspensions is attributable to the elongational flow properties of (AP/EP) medium. At critical gel state (ϕ = 35 vol.% and T = 100°C) and in gel state (ϕ ≥ 40 vol.%), the elongational viscosity exhibited the strain-softening behavior. These results strongly suggest that the strain softening results from the strain-induced disruption of the network structure of the SiO2 particles therein.

Linear and nonlinear viscoelasticity of an adhesion material for integrated circuit chips were investigated to control the processability. The material consists of acrylic polymer (AP) and epoxy oligomer (EP). EP content in AP/EP blend is 70 vol %. From the linear viscoelasticity, it was found that the iso-free volume state of AP/EP blend was 20°C lower than that of AP and the entanglement molecular weight Me of AP/EP was three times higher than that of AP. Nonlinear stress relaxation modulus G(t,γ) showed that the time-strain separability, G(t,γ) = G(t)h(γ), was applicable at long time above a characteristic time τk, where G(t) is linear relaxation modulus and h(γ) is the damping function. The τk value was estimated to be 10 s for AP/EP and below 0.1 s for AP at an iso-free volume state. (h(γ) for AP and AP/EP behaved like a usual linear homopolymer.) The time evolution of the elongational viscosity ηE(t) of each sample showed that AP/EP system exhibited strong strain hardening at , although AP did not show strain hardening at strain rate measured, when the data were compared at an iso-free volume state. These results strongly suggest that the strain hardening behavior of AP/EP is attributable to enhancement of the stretch of AP polymer chains by diluting EP oligomer chains. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A poly(vinyl chloride) $(\mbox{PVC,}\;{\rm M}_{\rm w} =102\times 10^3)$ di-octyl phthalate (DOP) gel with PVC content of 20 wt.% was prepared by a solvent evaporation method. The dynamic viscoelsticity and elongational viscosity of the PVC/DOP gel were measured at various temperatures. The gel exhibited a typical sol–gel transition behavior with elevating temperature. The critical gel temperature (Tgel) characterized with a power–law relationship between the storage and loss moduli, G′ and G″, and frequency ω, ${G}^\prime={G}^{\prime\prime}{\rm /tan}\;\left( {{n}\pi {\rm /2}} \right)\propto \omega ^{n}$ , was observed to be 152°C. The elongational viscosity of the gel was measured below the Tgel. The gel exhibited strong strain hardening. Elongational viscosity against strain plot was independent of strain rate. This finding is different from the elongational viscosity behavior of linear polymer solutions and melts. The stress–strain relations were expressed by the neo-Hookean model at high temperature (135°C) near the Tgel. However, the stress–strain curves were deviated from the neo-Hookean model at smaller strain with decreasing temperature. These results indicated that this physical gel behaves as the neo-Hookean model at low cross-linking point, and is deviated from the neo-Hookean model with increasing of the PVC crystallites worked as the cross-linking junctions.

We report the superconductivity in layered oxychalcogenide La2O2Bi3AgS6 compound. The La2O2Bi3AgS6 compound has been reported recently by our group, which has a tetragonal structure with the space group P4/nmm. The crystal structure of La2O2Bi3AgS6 can be regarded as alternate stacks of LaOBiS2-type layer and rock-salt-type (Bi,Ag)S layer. We measured low-temperature electrical resistivity and observed superconductivity at 0.5 K. The observation of superconductivity in the La2O2Bi3AgS6 should provide us with the successful strategy for developing new superconducting phases by the insertion of a rock-salt-type chalcogenide layer into the van der Waals gap of BiS2-based layered compound like LaOBiS2., Comment: 7 pages, 2 figures; to be published in J. Phys. Soc. Jpn

HTS current leads have been prepared by the TFA-MOD processed YBCO tapes. A current lead unit is composed of five YBCO tapes soldered to Cu caps at both ends and a GFRP board. The YBCO tape is 5 mm in width, 190 mm in length and about 120 ?m in overall thickness. The YBCO superconducting layer, 1.5 ?m in thickness, is formed on oxide buffer layers of GZO and CeO2 deposited on Hastelloy substrate tapes. Transport current is supplied through Ag layer deposited on YBCO layer. The YBCO tapes with critical current of about 170 A at 77 K in self-fields have been used for two 500 A-class current lead units. The transport current of 800 A was stably carried in liquid nitrogen without any voltage appearance on each tape. The voltage between both Cu caps linearly increased with increasing current, and it was about 350 ?V at 500 A. The low voltage at Cu joints results from low contact resistance between YBCO tapes and Cu caps, and causes small Joule heating at the Cu joints. Furthermore, the transport current of 1400 A was successfully applied in the current lead combined with two units in parallel. The heat leakage of the current lead unit composed of five YBCO tapes and a GFRP board between 77 K and 4.2 K is calculated to be 47 mW/0.5 kA, which is much smaller than that of conventional Cu current lead (1.2 W/kA). The small heat leakage results from high current performance and low thermal conductivity in the present HTS current lead.

The effect of hydrocarbon oil incorporation on the rheological and phase behaviors of poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) has been investigated. SEBS-A1 (neat SEBS) shows a presence of very long relaxation time mode even at the highest temperature carried out here. On the other hand, G′ of SEBS-A3 (oil concentration = 50 wt %) drastically decreases with increase of temperature at a critical temperature, which can be assigned to be order–disorder transition (ODT). The critical temperature was determined by two rheological criteria. Incorporation of hydrocarbon oil affects the ODT temperature. The rheological response is very sensitive to a few temperature increases around the ODT temperature. Above the critical temperature, G′ finally yields the terminal flow in the low frequency range. The morphological observation at various temperatures was determined using atomic force microscopy (AFM) equipped with environmental controller. This enabled in situ observation of structural change of SEBS induced by temperature and phase transition. We found that the layered texture, mostly aligned along the surface can be seen for SEBS-A1 ranging from room temperature to 230 °C, though the image contrast reduced by an increase of temperature. SEBS-A3 showed sphere domains at room temperature and also remains the structure at a critical temperature. The phase separated structure disappeared almost completely above ODT temperature, which was confirmed by the rheologial criteria. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 955–965, 2009

This paper provides the results of the MD simulations of the interaction between a screw dislocation and a copper precipitate in iron. From the results, the screw dislocation has an attractive interaction with the copper precipitate. Also, the dependence of the Critical Resolved Shear Stress (CRSS) for the screw dislocation to break away from the copper precipitate on the size of the precipitate and temperature is studied. Finally, the CRSS obtained by the MD simulations is modeled statistically using a Russel-Brown model. Then we found that an addition of the Peierls stress, which is calculated by the MD simulations, to the Russel-Brown model gives a good prediction of the CRSS.

Dynamic viscoelastic properties of blends of poly(methyl methacrylate) (PMMA) and poly(styrene-co-acrylonitrile) (SAN) with various AN contents were measured to evaluate the influence of SAN composition, consequently χ parameter, upon the melt rheology. PMMA/SAN blends were miscible and exhibited a terminal flow region characterized by Newtonian flow, when the acrylonitrile (AN) content of SAN ranges from 10 to 27 wt %. Whereas, PMMA/SAN blends were immiscible and exhibited a long time relaxation, when the AN content in SAN is less than several wt % or greater than 30 wt %. Correspondingly, melt rheology of the blends was characterized by the plots of storage modulus G′ against loss modulus G″. Log G′ versus log G″ plots exhibited a straight line of slope 2 for the miscible blends, but did not show a straight line for the immiscible blends because of their long time relaxation mechanism. The plateau modulus, determined as the storage modulus G′ in the plateau zone at the frequency where tan δ is at maximum, varied linearly with the AN content of SAN irrespective of blend miscibility. This result indicates that the additivity rule holds well for the entanglement molecular weights in miscible PMMA/SAN blends. However, the entanglement molecular weights in immiscible blends should have “apparent” values, because the above method to determine the plateau modulus is not applicable for the immiscible blends. Effect of χ parameter on the plateau modulus of the miscible blends could not be found. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Steady-shear measurements of suspensions of carbon blacks (CB) in polystyrene (PS)/di-(butyl phthalate) (DBP) solution were investigated as a function of volume fraction (ϕ) of CB to clarify the effect of the primary particle size and the structure of CB aggregates on the rheological properties. The suspensions show a typical shear-thinning behavior in the range of a shear rate studied. The Casson model was applied to evaluate the viscosity at infinite of shear rate η∞ and the yield stress σy for the suspensions. Relative viscosity η∞/ηm, (ηm: medium viscosity) thus obtained was compared to the high-frequency viscosity for the ideal hard-sphere silica suspensions to evaluate the effective volume fraction ϕeff of CB aggregates. The ϕeff value was larger for the higher-structure CB with higher DBP absorption value, irrespective of the primary particle size. The yield stress σy had almost the same ϕeff dependence for neutral furnace CB/(PS/DBP) suspensions, although it was larger for acetylene black (AcB)/(PS/DBP) suspensions. These results demonstrated that the effective volume fraction is the most important quantity to characterize the CB aggregates on the rheological properties. It was also found that the correction of the medium viscosity changes due to polymer adsorption on the CB surface is important since neutral furnace CB adsorbs PS polymers but AcB hardly adsorbs PS polymers in the solution. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

We investigated the dynamic viscoelasticity and elongational viscosity of polypropylene (PP) containing 0.5 wt% of 1,3:2,4-bis-O-(p-methylbenzylidene)-d-sorbitol (PDTS). The PP/PDTS system exhibited a sol–gel transition (T gel) at 193 °C. The critical exponent n was nearly equal to 2/3, in agreement with the value predicted by a percolation theory. This critical gel is due to a three-dimensional network structure of PDTS crystals. The elongational viscosity behavior of neat PP followed the linear viscosity growth function 3η + (t), where η + (t) is the shear stress growth function in the linear viscoelastic region. The elongational viscosity of the PP/PDTS system also followed the 3η + (t) above T gel but did not follow the 3η + (t) and exhibited strong strain-softening behavior below T gel. This strain softening can be attributed to breakage of the network structure of PDTS with a critical stress (σ c) of about 104 Pa.

The local magnetic state of SmRu4P12 in the possible octupole ordering phase was studied at 15 K by means of the zero field, longitudinal field, and transverse field muon spin rotation/relaxation methods. We observed that the internal field at each muon site consists of quasi-static and dynamical fields. A possible interpretation of the coexistent fields is discussed.

Linear viscoelastic properties of carbon black (CB) suspensions in a rosin-modified phenol resin-type varnish (Varnish-1) were studied as a function of volume fraction (ϕ) of CB and temperature (T) to clarify the effects of the primary particle size and the aggregate structure of CB particles on the rheological properties. All the CB/Varnish-1 suspensions showed a typical sol–gel transition behavior with an increase in ϕ. The critical gel behavior characterized with a power-law relationship between the storage and loss moduli (G′ and G″) and frequency (ω), G′ = G″/tan(nπ/2) ∝ ωn, was observed at a critical gel concentration (ϕcrit). At 30 °C, the critical relaxation exponents (n) were estimated to be 0.72 ± 0.02, irrespective of the primary particle size and aggregate structure of the CB particles. In contrast, the ϕcrit depended strongly on the aggregate structure although it hardly depended on the primary particle size. Both the n and ϕcrit values changed with T. The n values increased from 0.72 at 30 °C to 0.83 at 60 °C and the correspondent ϕcrit values decreased slightly with elevating T for each CB suspension. The increase in n with T indicated that the CB aggregate structures changed from plane-like to more straight with increasing T.

Poly(vinyl chloride) (PVC)/di-isononyl phthalate systems with PVC content of 45.5 (PVC8) and 70.4 wt% (PVC6) were prepared by a hot roller at 150 °C and press molded at 180 °C. The dynamic viscoelasticity and elongational viscosity of PVC8 and PVC6 were measured in the temperature range from 150 to 220 °C. We have found that the storage and loss shear moduli, G′ and G″, of PVC8 and PVC6 exhibited the power-law dependence on the angular frequency ω at 190 and 210 °C, respectively. Correspondingly, the tan δ values did not depend on ω. These temperatures indicate the critical gel temperature T gel of each system. The critical relaxation exponent n obtained from these data was 0.75 irrespective of PVC content, which was in agreement with the n values reported previously for the low PVC concentration samples. These results suggest that the PVC gels of different plasticizer content have a similar fractal structure. Below T gel, the gradual melting of the PVC crystallites takes place with elevating temperature, and above T gel, a densely connected network throughout the whole system disappears. Correspondingly, the elongational viscosity behavior of PVC8 and PVC6 exhibited strong strain hardening below T gel, although it did not show any strain hardening above T gel. These changes in rheological behavior are attributed to the gradual melting of the PVC crystallites worked as the cross-linking domains in this physical gel, thereby inapplicability of the of time–temperature superposition for PVC/plasticizer systems.

In the filled skutterudite compounds (RT 4 X 12 : R rare earth, T=Fe, Ru, Os, and X=pnictogen-ions), various attractive features have been found by replacing the constituent elements, e.g., metal–insulator transition in PrRu 4 P 12 , competing heavy fermion and multipolar ordered states in PrFe 4 P 12 , heavy fermion superconductivity in PrOs 4 Sb 12 , etc. Most of these features are realized probably by the unique crystal structure; R is embedded in the cage made of 12X and eight T ions, so that the strong c–f hybridization becomes a common feature irrespective of the constituent elements. The strong c–f hybridization in skutterudites enables the strongly correlated electron behaviors even in the systems containing rare-earth elements with more than one 4f-electron. The effect of X-replacement appears most apparently as a change in c–f hybridization, as is naturally inferred from the large difference in lattice constant. In addition to the c–f hybridization effect, it was recognized that f-electron's multipolar degrees of freedom and relatively small crystalline electric field splitting are important factors to understand the aforementioned novel phenomena.

We studied the characteristics of some thermoplastic elastomers (TPEs) using measurements of the temperature dispersion of the complex tensile modulus in the solid state, and the dynamic viscoelasticity and elongational viscosity in the molten state. The TPE samples included PVC/plasticizer-type TPEs and polymer alloy-type TPEs. The storage and loss shear moduli, G′ and G″, exhibited a power-law dependence on the angular frequency ω for most of the TPE samples measured. These findings indicate that these TPEs have long time relaxation mechanisms due to a self-similar fractal-like structure. The elongational viscosity behavior was different between the PVC/plasticizer-type TPEs and polymer alloy-type TPEs. The PVC/plasticizer-type TPEs exhibited strong strain hardening, while the other TPEs did not show any strain hardening. This difference is attributed to the morphology in these TPEs.

Electrokinetic soil remediation by electroosmosis and ionic migration is restricted to soluble substances. At a higher pH, the soil particles sorb more heavy metals, such as cadmium, than at a lower pH and the precipitation reactions of heavy metals are promoted. Both mechanisms make heavy metals immobile, rendering cleanup more difficult and electrokinetic extraction inefficient. Therefore, the acidification of soils is very important to increase the cleanup efficiencies of heavy metals, such as cadmium by electrokinetic method from contaminated soils. Meanwhile, hexavalent chromium is more mobile and easily soluble. Hexavalent chromium has high solubility in water and exists as chromate, monochromate or dichromate anions depending on the pH of the solutions. This hexavalent chromium is the chemical form requiring remediation. In this study, cadmium and hexavalent chromium transport are predicted with a simple numerical method in which electrical flow is coupled with hydraulic flow, and the sorption process in the soils is induced in the model. The effects of some factors such as electrode configuration, electric field strength and electrode spacing for saturated soils are investigated using this numerical model. The results obtained this study are summarized as follows: The two-dimensional electrode configurations containing cathode surrounded by three or more anodes rapidly remove cadmium from soils compared with one-dimensional electrode configuration. Meanwhile, in the removal of hexavalent chromium from soils, the two-dimensional electrode configurations containing anode surrounded by three or more cathodes can be effectively utilized compared with one-dimensional electrode configuration. A larger electrode spacing increases the processing time required, and it was also found that a larger electric field strength reduced the processing time required.

We have observed the flux penetration into a high- T c superconducting YBa 2 Cu 3 O 7− δ (YBCO) tape by a magneto-optical (MO) imaging technique in order to feed back to the R&D of processing. The MO images of YBCO coated conductor prepared by metal organic deposition using trifluoroacetates (TFA-MOD) showed many weak links such as periodic defect and other serious defects, which were corresponding to the dispersion of critical current along to length direction. Since the combination study of MO imaging with TEM observation revealed the reason of such defects, we could feed back to several processes. The new TFA-MOD tapes prepared by using an advanced process after using many innovations showed a homogeneous flux penetration observed by MO imaging, and then it is confirmed that the process went to higher stage rather than previous one.

We developed a new precursor solution that consists of copper naphthenate, and yttrium- and barium-trifluoroacetates (advanced TFA solution) that can make the heating rate during calcination increase while maintaining a high Jc. In this paper, we investigated the influence of HF gas generation on the calcination process in order to optimize an advanced TFA-MOD process. The high heating rate and/or low copper content in the starting solution lead to a low Jc. In both cases, a high generation rate of HF gas was observed. Consequently, it is clear that rapid HF gas generation leads to the formation of pores that cause a reduction in Jc values.

We have studied the magnetic and thermal properties of a single crystal of CePt3Si, which is a recently reported heavy-fermion superconductor with a superconducting transition temperature Tc = 0.75 K and a Neel temperature TN = 2.2 K. The overall experimental data are principally explained on the basis of the crystalline electric field (CEF) scheme. Even in the antiferromagnetic state, the CEF model applies well to the characteristic features in the magnetization curve. These results indicate the existence of a localized magnetic moment at the Ce site, with a considerably reduced ordered moment of 0.16 μB/Ce, and the strongly correlated conduction electrons are condensed into the superconducting state. We have also constructed the magnetic phase diagram including the superconducting phase for and [001].

The electrical resistivity ρ(T) of Y1−xUxPd3 (x = 0,0.05 and 0.2) and the lattice constants for x = 0 have been measured at high pressure. It is found that the cubic Cu3Au structure is stable up to 12 GPa at room temperature. The Kondo temperature TK was extracted from the ρ(T) curve and it was found that it increases with pressure. A logarithmic temperature dependence characteristic of the Kondo effect was found for x = 0.2 in the temperature range above about 0.5TK. Fermi liquid behaviour in ρ(T) for x = 0.05, i.e., , is observed and its stability at high pressure is discussed. The pressure dependence of the Kondo temperature TK is discussed using the Gruneisen parameters at TK, ΓK. It appears that the values of ΓK are the same for these two compounds (x = 0.05 and 0.2): ΓK = 12. The T-linear behaviour in ρ(T) for x = 0.2, which is characteristic behaviour for non-Fermi liquids, is collapsed by an application of pressure and typical Fermi liquid quadratic temperature dependence recovers at high pressure. From the result for x = 0.2, the power n of the temperature in is determined as 1.0 at ambient pressure and 1.9 at 5.8 GPa. It is pointed out that the hybridization effect due to the application of pressure gives rise to a crossover from a non-Fermi liquid state to Fermi liquid state. But the crossover temperature Tcr shows a pressure dependence different from that predicted by the two-channel Kondo model.

Viscoelastic properties of several types of multi-component polymer systems were studied. For the miscible blends of poly(styrene-co-acrylonitrile) (SAN) with several (co)polymers, the time-temperature superposition principle was applicable over the entire temperature range and the relaxation behavior was similar to that of a blend consisting of homologous polymers. Poly(vinyl chloride) (PVC)/plasticizer systems exhibited a typical critical gel behavior by changing PVC concentration and temperature. For the carbon black (CB) suspensions, three different types of the rheological behavior were observed: highly nonlinear, elasto-plastic feature, sol-gel transition type behavior, and the slow relaxation due to Brownian diffusion, with the affinity of suspending medium toward the CB particles. Similarity between the behaviors of CB suspensions and ABS polymer melts is also discussed.