A maximum power point tracking control method suitable for compact wind power generators with the passive self‐pitch‐controlled blade structure

This paper describes a maximum power point tracking (MPPT) control method for propeller‐type compact wind power generators with passive self‐pitch‐controlled blades, which quickly makes the output current and voltage converge on the maximum power point based on wind speeds detected from an anemometer. The voltage and current output from these wind power generators vary with wind speeds at locations such as the roofs of buildings. Transient characteristics of the voltage output from compact wind power generators have two modes because of the self‐pitch‐controlled blades: mode I in which the output voltage hardly increases and mode II in which it rapidly increases. Thus, in order to acquire the generated power effectively, irrespective of how the wind speeds may change, a method to perform the MPPT control while searching for mode II is needed. Thus, by judging the mode from the change of the sign of the time differential of the voltage deviation between sampling times, the MPPT control method proposed here makes the output current converge on the maximum point using relationships between the maximum power and optimal current which give the maximum power and the wind speed. Effectiveness of the proposed MPPT control method is verified through simulations and experiments using a wind tunnel. IEEJ Trans 2010 DOI: 10.1002/tee.20609     

An Opportunistic Directional MAC Protocol with Pulse/Tone Exchange in Wireless Ad-Hoc Networks

Wireless Personal Communications - This paper proposes a Medium Access Control (MAC) protocol using directional antennas in wireless ad-hoc networks, which achieves frame-collision reduction,...     

Robot motion design using bunraku emotional expressions – focusing on Jo-Ha-Kyū in sounds and movements*

One of the UNESCO intangible cultural heritages Bunraku puppets can play one of the most beautiful puppet motions in the world. The Bunraku puppet motions can express emotions without the so-called ‘Uncanny Valley.’ We try to convert these emotional motions into robot affective motions so that robots can interact with human beings more comfortable. In so doing, in the present paper, we present a robot motion design framework using Bunraku affective motions that are based on the so-called ‘Jo-Ha-Kyū,’ and convert a few simple Bunraku motions into a robot motions using one of deep learning methods. Our primitive experiments show that Jo-Ha-Kyū can be incorporated into robot motion design smoothly, and some simple affective robot motions can be designed using our proposed framework.     

Grafting of branched polymers onto nano-sized silica surface: Postgrafting of polymers with pendant isocyanate groups of polymer chain grafted onto nano-sized silica surface

To control the surface wettability of nano-sized silica surface, the postgrafting of hydrophilic and hydrophobic polymers to grafted polymer chains on the surface was investigated. Polymers having blocked isocyanate groups were successfully grafted onto nano-sized silica surface by the graft copolymerization of methyl methacrylate (MMA) with 2-(O-[1′-methylpropylideneamino]caboxyamino)ethyl methacrylate (MOIB) initiated by azo groups previously introduced onto the surface. The blocked isocyanate groups of poly(MMA-co-MOIB)-grafted silica were stable in a desiccator, but isocyanate groups were readily regenerated by heating at 150 °C. The hydrophilic polymers, such as poly(ethylene glycol) (PEG) and poly(ethyleneimine) (PEI), were postgrafted onto the poly(MMA-co-MOIB)-grafted silica by the reaction of functional groups of PEG and PEI with pendant isocyanate groups of poly(MMA-co-MOI)-grafted silica to give branched polymer-grafted silica. The percentage of grafting increased with increasing molecular weight of PEG, but the number of postgrafted chain decreased, because of steric hindrance. The hydrophobic polymers, such as poly(dimethylsiloxane) were also postgrafted onto poly(MMA-co-MOI)-grafted silica. It was found that the grafting of hydrophobic polymer and the postgrafting of hydrophilic polymer branches readily controls the wettability of silica surface to water.     

Kinetic Analyses of Solid-State Reactions with a Particle-Size Distribution

Kinetic analyses for the solid-state reactions of reactant particles in an assemblage with a particle-size distribution (PSD) have been reexamined for the reactions that proceed by the advance of the reaction interfaces inward toward the center of the individual reactant particles. The experimental kinetic curves for a particle assemblage are influenced by the existing PSD. It has been demonstrated that, even if PSD exists, a reliable activation energy E can be obtained from such overall kinetic curves by the empirical isothermal analysis without accounting for the PSD. The isoconversion methods, which enable us to determine the E value from the data points at a given fractional reaction of a series of experimental kinetic curves, are methodologically independent of the PSD. It is neccessary to incorporate the PSD into the kinetic equation to select an appropriate kinetic model and to evaluate the preexponential factor A . The method of kinetic calculation accounting for the PSD can be generalized, for the kinetic data under any thermal profiles, by extrapolating all the analytical conditions to infinite temperature. For the reaction characterized by the well-defined PSD and kinetic model function, the meaningful A value is obtained by the kinetic analysis at infinite temperature. Although the ability to discriminate the contracting geometry of the reaction interface in a single particle from the overall kinetic curve decreases with increasing PSD, the rate-controlling steps for the advance of the reaction interface, i.e., chemical reaction controlled or diffusion controlled, can be distinguised from each other even for the reactions with a fairly large PSD.     

木材经催化热分解向BTX和合成燃料的转化

以废木材生物质的有效利用为目的,使用粉粒流化床反应器,对3种木材进行了催化热分解实验,以4种催化效果不同的粒子作为流化床内的流化介质来考察催化热分解过程中介质颗粒、反应气体和热分解温度对产物分布的影响.木材的挥发性物质在700K时就已几乎分解出来,挥发性物质中的轻质芳香烃碳氢化合物（苯、甲苯、二甲苯和萘：BTXN）的收率随着热分解温度的升高而增加,1173K下达到3.1%（质量分数）,daf.在氢气气氛下,当作为流化介质颗粒Zn(3%,质量分数)/HZSM-5催化剂对木材进行催化热分解时,853K下可得到6.1%, daf的轻质芳香烃碳氢化合物的收率(BTX 5.5%,daf、萘0.6%,daf).而在活性很高的NiMo-A加氢催化剂下,在863K时,催化热分解产物几乎全为甲烷.     

Improvement of registration accuracy of a handheld augmented reality system for urban landscape simulation

The need for visual landscape assessment in large-scale projects for the evaluation of the effects of a particular project on the surrounding landscape has grown in recent years. Augmented reality (AR) has been considered for use as a landscape simulation system in which a landscape assessment object created by 3D models is included in the present surroundings. With the use of this system, the time and the cost needed to perform a 3DCG modeling of present surroundings, which is a major issue in virtual reality, are drastically reduced. This research presents the development of a 3D map-oriented handheld AR system that achieves geometric consistency using a 3D map to obtain position data instead of GPS, which has low position information accuracy, particularly in urban areas. The new system also features a gyroscope sensor to obtain posture data and a video camera to capture live video of the present surroundings. All these components are mounted in a smartphone and can be used for urban landscape assessment. Registration accuracy is evaluated to simulate an urban landscape from a short- to a long-range scale. The latter involves a distance of approximately 2000 m. The developed AR system enables users to simulate a landscape from multiple and long-distance viewpoints simultaneously and to walk around the viewpoint fields using only a smartphone. This result is the tolerance level of landscape assessment. In conclusion, the proposed method is evaluated as feasible and effective.     

Prediction of pressure–viscosity coefficient of lubricating oils based on sound velocity

The pressure–viscosity coefficient is an important parameter in tribology. Experimentally, it is calculated using the high‐pressure viscosity measurement. Also, the adiabatic bulk modulus is calculated using the sound velocity in the lubricating oil. Several lubricating oils are considered on the group basis such as traction oil, mineral oil, polyalphaolefin oil, perfluoropolyether oil and glycerol, depending on their molecular structure. Experimental pressure–viscosity coefficient is compared with the adiabatic bulk modulus. It is found that the pressure–viscosity coefficient increases exponentially with the adiabatic bulk modulus, and the relationship depends on the molecular structure of the lubricating oils. This study proposes two equations to predict the pressure–viscosity coefficient from the adiabatic bulk modulus based on sound velocity, one for the traction oil, and another for the paraffinic mineral oil and the polyalphaolefin oil. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis of mesoporous titania nanoparticles with anatase frameworks and investigation of their photocatalytic performance

In this research paper, we synthesize various types of mesoporous titania nanoparticles (MTNs) with suitable surface area and pore size while creating anatase frameworks by applying hydrothermal treatment or calcination at different temperatures. Wide-angle XRD patterns and N2 adsorption-desorption isotherms reveal that the MTNs with crystallized anatase frameworks can be synthesized after an optimized hydrothermal treatment. In contrast, calcination of MTNs at high temperature caused the collapse of mesoporous structure, resulted in drastic reduction of the surface area of the MTNs. In addition, we investigate the photocatalytic activity of the prepared MTNs by measuring the degradation of methylene blue (MB). The results show that the reaction rates of the photocatalytic MB decomposition strongly depend on the degree of crystallinity in the MTNs frameworks and on the surface area of MTNs.