Lateral Inhomogeneity in the Electronic Structure of a Conjugated Poly(3‐hexylthiophene) Thin Film

How annealing influences the morphology of a highly regioregular poly(3‐hexylthiophene) (RR‐P3HT) film at the substrate interface as well as the lateral inhomogeneity in the electronic structure of the film are elucidated. Whereas previous studies have reported that high‐molecular‐weight (MW) RR‐P3HT films tend to show low crystallinity even after annealing, it is found that high‐MW RR‐P3HT does show high crystallinity after annealing at high temperature for a long time. Photoemission electron microscopy (PEEM), X‐ray photoemission spectroscopy, and ultraviolet photoemission spectroscopy results clearly resolve a considerable lateral inhomogeneity in the morphology of RR‐P3HT film, which results in a variation of the electronic structure depending on the local crystallinity. The PEEM results show how annealing facilitates crystal growth in a high‐MW RR‐P3HT film.     

Design of plant safety model in plant enterprise engineering environment

Plant enterprise engineering environment (PEEE) is an approach aiming to manage the plant through its lifecycle. In such environment, safety is considered as the common objective for all activities throughout the plant lifecycle. One approach to achieve plant safety is to embed safety aspects within each function and activity within such environment. One ideal way to enable safety aspects within each automated function is through modeling. This paper proposes a theoretical approach to design plant safety model as integrated with the plant lifecycle model within such environment. Object-oriented modeling approach is used to construct the plant safety model using OO CASE tool on the basis of unified modeling language (UML). Multiple views are defined for plant objects to express static, dynamic, and functional semantics of these objects. Process safety aspects are mapped to each model element and inherited from design to operation stage, as it is naturally embedded within plant's objects. By developing and realizing the plant safety model, safer plant operation can be achieved and plant safety can be assured.     

Phospholipid polymer hydrogel formed by the photodimerization of cinnamoyl groups in the polymer side chain

We synthesized new polymers with both photocrosslinkability and biocompatibility by a random copolymerization of 4‐(4‐methoxycinnamoyl)phenyl methacrylate and 2‐methacryloyloxyethyl phosphorylcholine. These polymers were used as prepolymers to make a hydrogel by photoirradiation. Gelation began with 5 s of photoirradiation and reached an equilibrium state after 360 s of photoirradiation. The absorption maximum at 347 nm, attributed to the cinnamoyl group, disappeared with the photoirradiation time. That is, dimerization between cinnamoyl groups in the polymer proceeded and formed a hydrogel. The equilibrium water concentration of the hydrogels was more than 90%. Moreover, we succeeded in making a microshape hydrogel on glass by photoirradiation through a photomask. The window shape of the photomask was transferred to the hydrogel that was formed. We concluded that these photocrosslinkable polymers could be useful in preparing microfluidic devices for separating or immobilizing biomolecules and cells. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 44–50, 2007     

Intensely irradiated steel components: Plastic and fracture properties, and a new concept of structural design criteria for assuring the structural integrity

In order to develop a systematic and reasonable concept assuring the structural integrity of components under intense neutron irradiation, two basic tensile properties, true stress-true strain (TS-TS) curves and fracture strain, were investigated on an austenitic stainless steel and martensitic steel. Application of Swift equation is confirmed to a large plastic strain range of TS-TS curves. Fracture strain ?_f data were well correlated as ?_f + ?₀ = const. where ?₀ is the pre-strain representing the irradiation hardening.Based on those formulations and available experimental information, several critical issues to be dealt with in developing the concept were identified possible reduction in ductility, significant change in mechanical properties, remarkable cyclic softening and other unique cyclic properties observed during a high-cycle fatigue testing, and the redundancy of the plastic collapse concept to bending. Existing structural codes are all based on the assumption that there will be no significant changes in mechanical properties during operation, and of high ductility. Therefore, a new concept for assuring structural integrity is required for application not only to components with high ductility but also components with reduced ductility. First, potential failure modes were identified, and a new and systematic concept was proposed for preventing these modes of failure, introducing a new concept of categorizing the loadings by stability of deformation process to fracture (as type F and M loadings). Based on the basic concept, a detailed concept of how to protect against ductile fracture was given, and loading type-dependent limiting parameters were set.Finally, application of the detailed concept was presented, especially on determination of loading type (in numerical approach, the formulation of TS-TS curves and fracture strain derived above are needed), and on how to determine the limiting parameters as allowable limits. Experiments were done to identify the loading type of a tensile loading acting on a structure with a discontinuity. Tensile loadings acting on an intensely neutron-irradiated flat plate with a hole in the center cause plastic tensile instability and necking at the minimum ligament section but do not initiate any surface crack at the initiation of necking.     

Rapid sensing of trace ionic substances with the novel porous monolith type ion exchanger

Biological and chemical sensor with a rapid response in microlevel test is required for health and environmental monitor. A novel sensing due to porous ion exchanger with three-dimensional acceptor has been first attempted to develop a high-performance sensor. This porous monolith type ion exchanger has an open-cellular monolith structure with 5–50-μm diameter pores. The trace amount of inorganic ions dissolved in aqueous solutions can be quantitatively determined with the impedance given by the monolith, which attracts and adsorbs the ions rapidly. We have succeeded in detecting ions with a concentration as low as 10⁻⁷ mol. The porous ion exchanger has a potentiality as a high-performance device for biological and chemical sensing. POLYM. ENG. SCI., 47:1666–1670, 2007. © 2007 Society of Plastics Engineers     

Evaluation of hexabromocyclododecane in fish and marine mammal oil supplements

We analyzed the dietary fish and marine mammal oil supplements purchased from Japanese markets for hexabromocyclododecane (HBCD); 20 brands were analyzed by liquid chromatography–tandem mass spectrometry (LC/MS/MS). HBCD was detected in 15 of 22 samples, and the concentrations of all the HBCD isomers (α, β, and γ) ranged from <0.9 to 67 ng/g lipid weight. α-HBCD was the dominant residue among the HBCD isomers. However, the composition of HBCD isomers varied according to the sample type. We found that 1 sardine oil brand and 2 shark liver oil brands extracted from fish captured in seawater around Japan contained relatively high levels of HBCD, indicating that both the surface and deep seawaters around Japan may have been contaminated with HBCD.     

Molybdenum‐Catalyzed Stereospecific Deoxygenation of Epoxides to Alkenes

Mild and simple catalytic systems consisting of molybdenum(VI) dichloride dioxide [MoO₂Cl₂] as a catalyst and a phosphine as reductant have been developed for the stereospecific deoxygenation of epoxides to alkenes. The reactions using 1,2‐bis(diphenylphosphino)ethane (dppe) and triphenylphosphine (PPh₃) proceed with retention and inversion of stereochemistry, respectively. The mild reaction tolerates the presence of various functional groups and affords stereodefined substituted olefins in good yields.

     

In-situ measurement of microwave absorption properties at 2.45 GHz for the polycondensation of lactic acid

For the construction of a microwave-assisted organic synthesis plant, it is necessary to know the dielectric properties of the reaction system. Measurements of the dielectric properties of lactic acid aqueous solution, anhydrated lactic acid, oligo(lactic acid) and water, which are constituent materials in the polycondensation of lactic acid, confirm that dielectric properties decrease as reaction progresses. Calculated microwave penetration depths, obtained from the dielectric properties, show that microwaves penetrate deeply into the reaction system. This work should be useful for the development of microwave-assisted organic syntheses in the chemical industry.