The synthesis of a porous-type of TiO2 with rutile structure

The synthesis of a porous-type of TiO₂ with rutile structure was studied. The focuses were on the thermal treatment temperature and time. AEROXIDE® TiO₂ P 25, as a fumed TiO₂, was thermally treated in a vertical-type tubular furnace by the natural dropping method. Even though the thermal treatment time was less than 1?s, a drastic increase of polymorphism from anatase structure to rutile structure was observed. The relationships between the rutile structure transformation ratio and surface area of obtained porous type of TiO₂ were investigated depending on the thermal treatment temperature. The porous-type of fumed TiO₂ showed high dispersibility in the sedimentation test although is showed large particle size.     

Nanofibers with Bragg gratings from equidistant holes

We study nanofibers with Bragg gratings from equidistant holes. We calculate analytically and numerically the reflection and transmission coefficients for a single grating and also for a cavity formed by two gratings. We show that the reflection and transmission coefficients of the gratings substantially depend on the number of holes, the hole length, the hole depth, the grating period, and the light wavelength. We find that the reflection and transmission coefficients of the gratings depend on the orientation of the polarization vector of light with respect to the holes. Such a dependence is a result of the fact that the cross-section of the gratings is not cylindrically symmetric.     

Low-speed high-torque drive system applying vernier motor torque

The application of the direct drive system is increasing in the field of robot and factory automation because of controllability with high accuracy. However, it requires the motor high torque at low speed. Although the vernier motor presented by Lee in 1963 could produce the reluctance torque in low speed, it involved many problems to be solved. This paper studies the reluctance torque of the vernier motor using the finite-element field analysis. Since the increase of rotor slot number is effective in producing high torque, in the model here, there are not only winding slots but also small slots on the stator teeth surfaces. Also, the rotor slots are provided in the periphery of the core more than the total number of stator slots by the pole number. The calculated torques have agreed very well with the experimental results. A prominent feature of the control scheme is to control the armature current phase based on the detected rotor slot position. Thus there is no problem such as pull-in or pull-out in Lee's vernier motor. Then the instantaneous torque is controlled by the amplitude of armature current. The experimental results on both the speed control and the position control also are shown in this paper.     

Stimulated Raman Scattering with Strong–Coupling in Solid Hydrogen

It is shown through stimulated Raman scattering in parahydrogen crystal that strongly coupled dressed states on the field–matter interacting system are established in the far off–resonant condition, and that the phase–matching for the parametric anti–Stokes generation process is realized without strict restriction of the medium refractive index dispersion.     

Engineering study of continuous supercritical hydrothermal method using a T-shaped mixer: Experimental synthesis of NiO nanoparticles and CFD simulation

In the synthesis of metal oxide fine particles by continuous supercritical hydrothermal method, rapid mixing of starting solution with supercritical water is a key factor for producing nanoparticles that have a narrow size distribution. In this paper, continuous hydrothermal synthesis of NiO nanoparticles from Ni(NO₃)₂ aqueous solution at 400 °C and 30 MPa was carried out with T-shaped mixers and the effect of inner diameter, flow rate, and mixing directions on the particle size was examined. The computational fluid dynamics (CFD) simulation of the mixers was performed to evaluate the heating rate of the starting solution. When the inner diameter of the T-shaped mixer was decreased from 2.3 to 0.3 mm and the flow rate was increased from 30 to 60 g/min, the produced NiO particle size decreased remarkably from 54.3 to 20.1 nm. This trend of the decrease in particle size could be described as a function of the heating rate. The experimental and CFD results showed the detail regions of local heating that correlated with the NiO nanoparticle size.     

Behavior Analysis of Internal Feedback Bridging Faults in CMOS Circuits

In this paper we analyze fault behaviors of internal feedback bridging faults. To investigate their behaviors, we use a simple circuit model consisting of 2-input NAND gate and NOT gate. From analysis results, we find that behaviors of internal feedback bridging faults are more complex than those of external feedback bridging faults. We expose that they cause IDDQ-only failure, internal latch and internal oscillation as well as latch and oscillation behavior. These phenomena are caused by the following facts: formation of an electrically conducting feedback loop and connection of the feedback loop with the circuit output depend on input values of the circuit, and the feedback loop is often alive only within the circuit. We also discuss methods for detecting this kind of fault.     

Proposal of Fault Diagnosis of Analog Circuits by Combining Operation-Region Model and X–Y Zoning Method: Case Study

We propose a method of diagnosing analog circuits that is achieved by combining an operation-region model and an X–Y zoning method. The X–Y zoning method can be used to detect faults in analog circuits by using the relationship between circuit inputs and outputs. The operation-region model can be used to analyze/model circuit behaviors by utilizing changes in the operation regions of MOS transistors in a circuit. Operation regions are obtained from transistor node voltages at sampling time corresponding to a particular excitation of the input value and the corresponding output value. Since we developed a data processing method to handle data discretely, we could implement a procedure for diagnosis based on the preset test, which is a method of diagnosing digital circuits. We demonstrated the effectiveness of our method by applying it to ITC’97 benchmark circuits with hard and soft faults. We found that the diagnostic resolution is one for every fault.     

Evaluation and application of oil-immersed zinc oxide elements enclosed in pole-mounted distribution transformers

Voltage due to lightning surge is now a major problem to be overcome to ensure full reliability of any power supply. Hence, gapless oil-immersed surge arresters using zinc oxide elements have been applied to pole transformers. These surge arresters are used as a means of insulation coordination for pole transformers. These arresters contribute to the reduction of the number of failure of pole transformers. This paper describes applications and effects of specially developed oil-immersed surge arresters in pole transformers on 6.6-kV distribution lines. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 121(2): 37–46, 1997     

Bilingualism and education.

The concept of bilingualism as applied to individual children and to educational programs is discussed, and the history of research on bilingual children and bilingual education programs in the United States is reviewed. Bilingualism has been defined predominantly in linguistic dimensions despite the fact that bilingualism is correlated with a number of nonlinguistic social parameters. The linguistic handle has served policymakers well in focusing on an educationally vulnerable population of students, but the handle is inadequate as the single focus of educational intervention. Future research will have to be directed toward a multifaceted perspective of bilingualism as a phenomenon embedded in society. (PsycINFO Database Record (c) 2010 APA, all rights reserved)