Adhesion between polymer surface modified by graft polymerization and tissue during surgery using an ultrasonically activated scalpel device

In the field of surgery, achieving adhesion between a polymer implant and tissue poses a challenge considering that suturing is not appropriate for the stability of such implants. An ultrasonically activated scalpel that generates heat by mechanical vibration and promotes adhesion between a polymer implant and native tissue by pressing the two materials together has very good potential for application in the field. To determine the type of polymer that is suitable for the purpose, we investigated polyethylene (PE) and polystyrene (PS) films, the surfaces of which were activated by corona discharge. Graft polymerization was then performed on the corona‐treated surfaces to vary their properties. The corona‐treated PE and PS films grafted with poly(acrylic acid), poly(methacrylic acid), poly(vinyl benzylacrylic acid), and poly(hydroxylethyl acrylate), respectively, adhered to the tissue when the ultrasonically activated scalpel was applied. The heat generated by the mechanical vibration and the applied pressure enabled the carboxyl or hydroxyl groups to bond with the proteins in the extracellular matrix. We therefore concluded that it was possible to integrate this technique in the development of new types of polymer devices that could be stably implanted in a living body. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40885.     

Present Status of the Nd:YAG Thomson Scattering System Development for Time Evolution Measurement of Plasma Profile on Heliotron J

A new high repetition rate Nd:YAG Thomson scattering system is developed for the Heliotron J helical device.A main purpose of installing the new system is the temporal evolution measurement of a plasma profile for improved confinement physics such as the edge transport barrier (H-mode) or the internal transport barrier of the helical plasma.The system has 25 spatial points with ～10mm resolution.Two high repetition Nd:YAG lasers (>550mJ@ 50Hz) realize the measurement of the time evolution of the plasma profile with ～10ms time intervals.Scattered light is collected by a large concave mirror (D=800 mm,f/2.25) with a solid angle of ～100 mstr and transferred to interference filter polychromators by optical fiber bundles in a staircase form.The signal is amplified by newly designed fast preamplifiers with DC and AC output,which reduces the low frequency background noise.The signals are digitized with a multi-event QDC,fast gated integrators.The data acquisition is performed by a VME-based system operated by the CINOS.     

Experimental investigation on optimization of invert trap configuration for sewer solid management

Invert traps have been successfully used to collect sediments at convenient locations within the sewer network, where large volumes of solids can be stored. In the present study, experiments have been performed in 15 cm wide and 5 m long channel for the measurement of retention ratios of five different invert trap configurations (namely, rectangular, trapezoidal with one side vertical, trapezoidal, trapezoidal with rectangular base, rectangular with trapezoidal base) having top width of 32 cm and depth of 28 cm with slots of three different sizes (namely, 5, 9 and 15 cm) for the flow of seven different sediment types (namely, two types of sand, glass beads and four types of plastic beads) at different flow rates for each trap. The flow rates selected in present study cover entire range of flow rate expected in channels during dry weather flow and monsoon. Flow field and retention ratio predictions for each invert trap configuration have been carried out using CFD modeling with the help of FLUENT software using Renormalization Group (RNG) k–ε along with Discrete Phase Model (DPM). The simulation results are capable of showing particle trajectories, the effect of flow rate and trap geometry on the flow patterns, developed within the trap. Based on CFD modeling and experimental measurements, it is concluded that the invert trap having rectangular shape with trapezoidal base is the most efficient trap configuration with highest sediment retention ratio.     

Adaptive set‐point regulation of discrete‐time nonlinear systems

In this paper, adaptive set‐point regulation controllers for discrete‐time nonlinear systems are constructed. The system to be controlled is assumed to have a parametric uncertainty, and an excitation signal is used in order to obtain the parameter estimate. The proposed controller belongs to the category of indirect adaptive controllers, and its construction is based on the policy of calculating the control input rather than that of obtaining a control law. The proposed method solves the adaptive set‐point regulation problem under the assumption that the target state is reachable for each fixed parameter value. Additional feature of the proposed method is that Lyapunov‐like functions have not been used in the construction of the controllers. Copyright © 2015 John Wiley & Sons, Ltd.     

Introduction of sulfhydryl groups and disulfide linkage to mungbean 8Sα globulin and effects on physicochemical and functional properties

Sulfhydryl groups and disulfide bond were introduced in mungbean's major storage protein, 8Sα globulin, by protein engineering to improve structural stability and functional properties. Five modified proteins or mutants (F59C, I99C, A213C, one free sulfhydryl group; I99C/A213, one disulfide bridge; F59C/I99C/A213C, one free sulfhydryl group and one disulfide linkage) were expressed in Escherichia coli at a yield similar to that of the unmodified protein or wild type (WT) in soluble form (38%). The number of introduced groups in the mutants was confirmed by Ellman analysis. Mutant and WT proteins exhibited similar elution patterns on gel filtration indicating their trimeric native conformation. Mutants had 2 to 3.8 °C higher T_m values than WT and were digested by chymotrypsin at 52–58% in 60 min but exhibited different digestion patterns. All mutants showed greater hardness of heat-induced gels than WT, especially I99C/A213C and F59C/I99C/A213C. Results indicate the improved structural stability of the modified 8Sα globulin.     

A Method for Reducing the Dead‐Time Voltage and Impedance Voltage in a Series Voltage Compensator

Many research groups are developing series voltage compensators. In a series converter, since a transformer is used in series in the power system, the power system current flows into the voltage source inverter through the transformer. The inverter current, which is determined by the transformation ratio, gives rise to an error voltage that consists of a dead‐time voltage and an impedance voltage. The error voltage is generated even when the reference voltage is zero. This paper describes the mechanism by which the error voltage occurs and proposes a method for reducing the error voltage. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(3): 85–93, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22333     

A chemically amplified molecular glass resist with an ionic photoacid generator and a single protection group

A molecular glass resist with an ionic photoacid generator and a single protection group (MR‐1) has been developed. MR‐1 exhibited good thermal properties, such as a 5% weight loss temperature (T_d5%) of 167°C and a glass transition temperature (T_g) of 80°C. MR‐1 showed the good sensitivity of 80 μC/cm² and high contrast of 4.9 with e‐beam exposure (50 keV). A relatively high resolution of 50 nm and low Line‐Edge‐Roughness of 3.8 nm were obtained by e‐beam exposure (100 keV). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39769.     

To react or not to react? Intrinsic stochasticity of human control in virtual stick balancing

Understanding how humans control unstable systems is central to many research problems, with applications ranging from quiet standing to aircraft landing. Increasingly, much evidence appears in favour of event-driven control hypothesis: human operators only start actively controlling the system when the discrepancy between the current and desired system states becomes large enough. The event-driven models based on the concept of threshold can explain many features of the experimentally observed dynamics. However, much still remains unclear about the dynamics of human-controlled systems, which likely indicates that humans use more intricate control mechanisms. This paper argues that control activation in humans may be not threshold-driven, but instead intrinsically stochastic, noise-driven. Specifically, we suggest that control activation stems from stochastic interplay between the operator''s need to keep the controlled system near the goal state, on the one hand, and the tendency to postpone interrupting the system dynamics, on the other hand. We propose a model capturing this interplay and show that it matches the experimental data on human balancing of virtual overdamped stick. Our results illuminate that the noise-driven activation mechanism plays a crucial role at least in the considered task, and, hypothetically, in a broad range of human-controlled processes.     

Enhanced Light Storage of SrAl2O4 Glass‐Ceramics Controlled by Selective Europium Reduction

A luminescent Eu, Dy: SrAl₂O₄ glass‐ceramics with high transparency in the visible region was successfully synthesized using the frozen sorbet technique with the control of O₂ partial pressure () for the oxidation of Eu²⁺ ions. The glass‐ceramics include Eu²⁺, Eu³⁺, and Dy³⁺ ions, and thus exhibits three characteristic types of emission bands, 4f–5d at around 520 nm (Eu²⁺ ions), 4f–4f at 610 nm (Eu³⁺ ions), and 480 nm (Dy³⁺ ions). The Eu, Dy: SrAl₂O₄ glass‐ceramics provide remarkable long‐persistent luminescence under dark condition. The glass‐ceramics also exhibits color‐changing luminescence in the visible region based on their remarkable light storage properties. The luminescent Eu, Dy: SrAl₂O₄ glass‐ceramics using the frozen sorbet technique with control of are promising materials for application in novel photonic and light storage materials.