How to obtain magnetocapacitance effects at room temperature: The case of Mn-doped BiFeO3

The magnetoelectric properties of a rhombohedrally distorted perovskite BiFe_0.7Mn_0.3O₃ are reported. An anomaly in the dielectric constant, related to enhanced thermal fluctuations around the antiferromagnetic transition, was induced near room temperature by the substitution of Mn for Fe in BiFeO₃. This substitution also brings about non-trivial magnetocapacitance effects at room temperature.     

Effect of aromatic substitution on phase behavior of blends of halogenated polystyrene and conventional polystyrene

Miscibility phase behavior in blends of poly(bromostyrene) with polystyrene (PS) has been investigated by means of time‐resolved light scattering, optical microscopy, and DSC. Cloud point phase diagrams of blends of conventional PS with poly‐(2‐bromostyrene) (P2BrS), poly‐(3‐bromostyrene), and poly‐(4‐bromostyrene) of comparable molecular weights were established by light scattering. Of particular interest is the fact that ortho, meta, and para substitutions in the styrenic aromatic rings of poly(bromostyrene) show profound effects on the composition–temperature phase diagrams of their blends with PS, exhibiting a lower critical‐solution temperature (LCST), an upper critical solution temperature (UCST), and combined LCST/UCST diagrams, respectively. Poly‐(2‐chlorostyrene) exhibits an LCST behavior very close to that of the P2BrS blend, suggesting that these types of halogen atoms may be inconsequential to phase behavior. A similar study has been extended to a PS blend containing commercial brominated PS (66 mol % bromine substitution) to determine what location of bromine substitution is crucial for miscibility enhancement in the flame‐retardant brominated PS blends. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1605–1615, 2001     

Iwasawa invariants of Λ-adic representation

It is a classical result that the number of primes ? for which τ(?) vanishes has Dirichlet density 0, where τ(?) is the Ramanujan τ function. We study an analogous question that arises in studying the Λ-adic representation whose image is full. In particular, we show that the set of primes ? for which the trace of the Frobenius at ? has positive μ-invariant has Dirichlet density 0. We also discuss the analogous Dirichlet densities related to λ-invariants.     

Autothermal reforming of methane to syngas for Fischer-Tropsch synthesis with promoted palladium and a fast start-up device

In this study, a Pd catalyst was prepared with promoters such as CeO₂, BaO and SrO in a washcoated form on a metallic monolith for autothermal reforming of methane to syngas for the Fischer-Tropsch synthesis. A reactor was installed with an electric heater in the form of the metallic monolith as a start-up device instead of a burner with which stable and fast start-ups (within 4 min) were achieved. Gas hourly space velocity and O₂/CH₄ governed, methane conversion, while H₂O/CH₄ controlled H₂/CO ratio. A methane conversion of approx. 96%, H₂+CO selectivity of approx. 85%, and H₂/CO of approx. 2.6 were obtained under the conditions of gas hourly space velocity (GHSV) at 103000 h^?1, O₂/CH₄=0.7 and H₂O/CH₄=0.35.     

A Sensitive and Selective LC-MS Method for the Determination of Lurasidone in Rat Plasma,Bile, and Urine

A liquid chromatography-mass spectrometry (LC-MS) assay was developed and validated for the quantification of lurasidone, an atypical antipsychotic drug, in rat plasma, bile, and urine. Rat plasma, bile, or urine samples were processed by liquid–liquid extraction and injected onto an LC-MS system for the quantification of lurasidone and ziprasidone (an internal standard). Lurasidone and ziprasidone were separated from endogenous substances using a Gemini C6-Phenyl column with mixture of acetonitrile and 0.1 % formic acid (80:20, v/v) as the mobile phase. Quantification was performed using the selected ion monitoring mode at m/z 493 for lurasidone and m/z 413 for the IS. The detector response was specific and linear for lurasidone in the concentration range 5–5,000 ng mL⁻¹ The intra- and inter-day accuracy and precision of the method were determined to be within the acceptable criteria for assay validation guidelines. In addition, lurasidone was stable under a variety of processing and handling conditions. Lurasidone concentrations could be readily measured in rat plasma, bile, and urine samples up to 24 h after an intravenous or oral administration, suggesting that the assay can be used in pharmacokinetic studies of lurasidone in rats.

     

The influence of microcrystalline cellulose grade on shape and shape distributions of pellets produced by extrusion-spheronization.

In this study, five microcrystalline cellulose (MCC) grades were physically characterized and their extrusion-spheronization behaviours were characterized in terms of water requirements and pellet shape profiles. It was found that the MCC grades differed significantly in the physical properties investigated. Physical properties of MCC were found to influence the water requirement for extrusion-spheronization. MCC grades of higher bulk densities, lower porosities and water retentive capacities required less water to produce pellets of equivalent size. These MCC grades were also found to produce pellets of lower sphericity and wider shape distributions. Packing of MCC particles within the agglomerate played a role in determining amount of water retention and pellet rounding during spheronization. However, there was a limit to the influence of packing density on the rate of pellet rounding because poor packing resulted in higher water retentive capacity, which also limited the rate of rounding.     

Structure of liquid water with ST2 model potentials in the temperature interval 273–373 K

Ufa Aviation Institute. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 4, pp. 69–73, July–August 1990.     

Sonocrystallization of polycarbonate melts

In this paper, we showed the simplified continuous process to crystallize the polycarbonate (PC) melts using sonocrystallization which is based on ultrasonic cavitation and ‘hot spot’ theory. High power ultrasonic wave was introduced to crystallize the PC prepolymers which is generally used for solid‐state polymerization (SSP) to obtain the ultra‐high molecular weight PCs. The structure and properties of PC treated with ultrasonic wave such as torque changes and crystallinities were studied. The experimental results showed that ultrasonic wave could improve the crystallinities of PCs and sonication time was proportional to their crystallinity. This is attributed to the decrease of the specific volume and the resulting shrinkage is compensated by a flux of a polymer melt toward the crystallization front. Torque data were collected directly from the Haake internal mixer and crystallinities were evaluated from differential scanning calorimeter (DSC). This process is an environmentally benign process so that no additional solvents or treatments are needed and will be very useful in the conventional solid‐state process which is used industrially. Copyright © 2007 John Wiley & Sons, Ltd.     

Solid phase synthesis of benzamidine-derived sulfonamide libraries

Using solid phase synthesis, a library has been constructed of benzamidine-derived sulfonamides which have strong inhibitory activity against blood coagulant thrombin. The library compounds were obtained in good yield and high purity. This revised version was published online in August 2006 with corrections to the Cover Date.