Effect of Hot Band Annealing on Magnetic Properties in 3% Si Grain‐oriented Electrical Steels

Hot band annealing is known to be a prerequisite for good magnetic properties irrespective of manufacturing methods in grain‐oriented Fe‐3 wt.% Si electrical steels. In this study, the effects of hot band annealing on magnetic properties were investigated in 3% grain‐oriented electrical steels of low soluble AI contents and one‐stage cold rolling. Microstructure and precipitate distribution were compared with hot band annealing conditions. Secondary recrystallization behaviour with hot band annealing condition was also discussed.     

The Principles of Eliminating Pulsating Torque in Current Source Inverter Induction Motor Systems

The problem of reducing the pulsating torque in current source inverter induction motor systems is investigated. Two typical approaches presented in recent publications are analyzed by making clear 1) the correlation among the current harmonics and the torque harmonics, and 2) the conceptual contradiction existing between these two approaches. By synthesizing the analyzed results, fundamental principles for treating the current harmonics and torque harmonics are established. In addition, the method for evaluating the degree of torque ripple is described, along with a proposed criterion for torque ripple content. By applying this criterion to these two approaches, objective estimates of degree of torque pulsations, which were unfeasible so far, are now made possible.     

An H∞ deconvolution filter and its application to ultrasonic nondestructive evaluation of materials

Deconvolution can be a valuable technique for interpreting results of ultrasonic nondestructive evaluation (NDE) tests of materials. This is especially true for state of the art hybrid materials. In this paper, a new H_∞ deconvolution filter is presented. The filter is applied to typical ultrasonic NDE data, including through-transmission data for aluminum and composite samples. The results are compared to those obtained from a Wiener deconvolution filter. The performance of the H_∞ filter is as good or better than the performance of the Wiener filter.     

Reflection mode scanning near-field optical microscopy analyses of integrated devices

Ultra-large-scale integrated devices have been investigated by a reflection mode scanning near-field optical microscope designed for semiconductor analyses. Although it could be found that imaging the reflectivity of metal structures buried underneath thin, optically transparent passivation layers is practicable, shading of the reflected light by the SNOM probe complicated the interpretability of the achieved results. This issue has been overcome by using the SNOM probe as both illumination source and detector, simultaneously. The application of focused ion beam milling to the probes has allowed the increase of the transmittivity of the probes to such an extent that coated fibres could be utilized and the interpretability of the results could be enhanced. Furthermore, the investigated structures are of great interest for an investigation of z -motion artefacts, as the presence of the polished passivation layers allows topographical influences to be distinguished from pure optical contrast.     

Efficient white organic light-emitting diodes with mixed electron transporting layers

The authors demonstrated phosphorescent white organic light-emitting diodes (PHWOLED) with mixed electron transporting layers (M-ETL) using 4,7-diphenyl-1,10-phenanthroline (BPhen)/4,4′-bis (carbazol-9-yl)biphenyl (CBP). The M-ETL PHWOLED exhibited the optimum balance of holes and electrons, owing to the low electron mobility of the CBP M-ETL. The optimized PHWOLED showed a peak current efficiency of 16.85 cd/A and a peak external quantum efficiency of 7.32%.     

Inverse Opal Scaffolds with an Embossed Surface Pattern Prepared from Sticky Golf‐Ball‐Shaped Microparticle Assemblies

Inverse opal scaffolds presenting an embossed‐pattern surface are prepared from colloidal crystal assemblies of uniformly sized golf‐ball‐shaped microparticles. Post‐treatments, such as thermal annealing during the bridging of the microparticles for opal preparation, are avoided to prevent deterioration of surface patterns of the sacrificial template. This presents a new approach to increase the surface‐area‐to‐volume ratio (SAV) by the alteration of morphological features in sophisticated 3D structures that remain largely unexamined owing to difficulties in their preparation. Previous results observed in 2D surfaces that show effective performance improvement through an increase in contact area, especially in biomedical applications, also appear applicable to patterned inverse opal scaffolds based on comparable results obtained from cell cultures. As the field of application of opal and inverse opal structures is expanding due to their unique structural advantages, such as 3D interconnectivity and periodic structures, our strategy opens the door for the use of patterned surfaces on highly sophisticated 3D structures, improving their performance via an increase in SAV.     

Quasi-Static Axial Damping of Poroviscoelastic Cylinders

Design of infrastructure materials with inherent material damping may help dissipate energy during dynamic loading events such as earthquakes, thereby reducing structural damage and risk of collapse. One possible method to enhance damping of cementitious materials such as concrete is to utilize poromechanical damping. To evaluate the potential damping associated with the poromechanical effect and to aid in the design of high damping porous materials such as concrete, approximate closed-form solutions have been derived for poromechanical damping as a function of frequency, maximum damping, and critical damping frequency for axially loaded solid and hollow cylinders. The effect of inherent viscoelastic damping of the porous material body was included in the analysis, which indicated that inherent viscoelastic damping could be superposed on poromechanical damping to predict overall damping capacity. Simulations indicate that poromechanical damping may be significant for cementitious materials if designed appropriately.     

Spark Plasma Sintered Hydroxyapatite/Multiwalled Carbon Nanotube Composites With Preferred Crystal Orientation

Hydroxyapatite (HA) and its nanocomposites reinforced with low loading levels of multiwalled carbon nanotubes (MWNTs) are prepared by spark plasma sintering process. The structure, morphology, and hardness of sintered HA and MWNT/HA nanocomposites are characterized by means of X‐ray diffraction (XRD), scanning electron microscopy and nanoindentation techniques. XRD results show that the orientation of crystallographic planes of sintered HA are highly related to the applied pressure direction. The perpendicular section of sintered MWNT/HA nanocomposites shows predominantly oriented HA a‐and b‐planes while the parallel section displays a dominant c‐plane orientation. The hardness of MWNT/HA nanocomposites improves considerably with increasing MWNT content.     

Improvement of gastroprotective and anti-ulcer effect of kenaf seed oil-in-water nanoemulsions in rats

Food Science and Biotechnology - Kenaf seed oil-in-water nanoemulsions (KSON) and kenaf seed oil-in-water macroemulsions were produced to access their gastroprotective effect against indomethacin-...