Look where you're going [robotic wheelchair]

We propose a robotic wheelchair that observes the user and the environment. It can understand the user's intentions from his/her behaviors and the environmental information. It also observes the user when he/she is off the wheelchair, recognizing the user's commands indicated by hand gestures. Experimental results show our approach to be promising. Although the current system uses face direction, for people who find it difficult to move their faces, it can be modified to use the movements of the mouth, eyes, or any other body parts that they can move. Since such movements are generally noisy, the integration of observing the user and the environment will be effective in understanding the real intentions of the user and will be a useful technique for better human interfaces.     

A visual-inspection system using a self-organizing map

Visual inspections by hand often cause bottlenecks in production processes in industries. Therefore, it is desirable to be mechanized and automated. In order to satisfy these requirements, we apply image recognition using a self-organizing map (SOM) to visual inspection equipment. The SOM maps high-dimensional input data onto a low-dimensional (typically two-dimensional) space. Through the mapping, the data are automatically clustered based on their similarity. Any unknown data which are input onto the self-organized map are also mapped onto it according to their similarity. The categories of the unknown data are thus recognized based on their positions on the map. The reason we use a SOM for inspections is that users can then know the similarity distribution of all data at a glance on the map, and understand the mechanism of the recognition visually. We have developed a visual inspection system using a SOM, and have evaluated it using actual product images. We have obtained high recognition accuracies of 98% and 96% for one- and two-inspection-point tests, respectively, for a real industrial product.     

Development of a parallel detection and processing system using a multidetector array for wave field restoration in scanning transmission electron microscopy

A parallel image detection and image processing system for scanning transmission electron microscopy was developed using a multidetector array consisting of a multianode photomultiplier tube arranged in an 8 x 8 square array. The system enables the taking of 64 images simultaneously from different scattered directions with a scanning time of 2.6 s. Using the 64 images, phase and amplitude contrast images of gold particles on an amorphous carbon thin film could be separately reconstructed by applying respective 8 shaped bandpass Fourier filters for each image and multiplying the phase and amplitude reconstructing factors.     

Synthesis and characterization of spinning poly(acrylonitrile‐co‐silk fibroin peptide)s

A novel spinning acrylic polymer containing silk protein was synthesized by copolymerization of acrylonitrile (AN) and silk fibroin peptide (SFP) modified by acryloyl chloride (AC) with vinyl groups. From results of the examination to the chemical compositions, we established that the modified SFP is more reactive than AN in the copolymerization. The intrinsic viscosity values of these copolymers showed that the copolymers have good spinnability, which were synthesized under the condition of adding a trace of metal ions into the synthesizing solvent. These copolymers exhibited good thermal property. The fiber based on the poly(acrylonitrile‐co‐silk fibroin peptide) was prepared and characterized by SEM, FTIR measurement of its shell and core flakes, and moisture absorption. The fiber exhibited a smooth surface and could be assumed to have excellent adhesive property between SFP and PAN. Furthermore, these fibers showed a core–shell structure and excellent moisture absorption. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1540–1547, 2004     

The influence of molecular weight of acid dyes on the yield stress of dyed nylon monofilament

The yield stress of nylon filament dyed with several acid dyes has been determined as a function of dye content and the molecular weight of acid dyes. The nylon filament dyes with acid dye has greater yield stress than undyed one. The relation between the increment of the yield stress (f) due to the adsorption of acid dye and the dye content (C) in the filament can be expressed by parameters A and B as log f = A log(C ? _C) + B, where C₀ is the dye content under which no contribution to the yield stress is observed and C₀ depends on the number of sulfonic groups in acid dye. It is found that these parameters A and B are expressed by M (the difference between the molecular weight of acid dye and the weight of SO₃Na groups in it) as A = 1 ? 100/M, B = k₁ M^k2, where k¹ and k² are the constants which depend on the parent chemical structure of dyes. The parameters A and B are expected to give available informations as to the physical state of adsorbed dye on nylon filament.     

The physicochemical parameters determining the size of agglomerate prepared by the wet spherical agglomeration technique

Lactose samples of five different particle sizes from 31 to 261 μm dispersed in chloroform were agglomerated with a small amount of saturated aqueous lactose solution which acted as a bridging liquid to wet the particles preferentially. The effects of raw particle size and the amount of bridging liquid on the average size of resultant agglomerate were investigated.

The agglomerate size increased with decreasing size of lactose. This effect was enhanced by increasing the amount of bridging liquid for lactose less than 79 μm. A linear correlation on a log—log plot was observed between the agglomerate size and the saturation ratio of bridging liquid. The slope increased with decreasing particle size of lactose. The size distribution of agglomerates was also determined for the particle size of lactose and the amount of bridging liquid used. The physicochemical properties of the bridging liquid, i.e. contact angle and interfacial tension, were also taken into account for interpreting the agglomerate size. The correlation between the agglomerate size and the above parameters was represented quantitatively by eqn. (10) in the text. The parameter n, which varies directly with agglomerate size, increased with increasing saturation ratio, or with decreasing lactose particle size.     

Some aspects of the biology of Nile perch,Lates niloticus,in the open waters of Lake Victoria,Kenya

Samples (6404) of Nile perch were collected monthly from commercial catches between June 2014 and June 2015. The total length (cm), weight (g) and sex of fish were all determined in the field, with 3771 (59%) being male and 2059 (32%) being female fish, for an overall sex ratio of 1.83:1.00 (male: female). The average length and weight for all fish were 55.38 ± 0.14 cm TL and 2355.10 ± 22.30 g, respectively. The size of male fish ranged from 15.5 to 128.5 cm TL and weighed between 190 and 25 000 g, whereas that of female ranged from 21.0 to 130.0 cm TL and weighed between 124 and 25 800 g. The value of the regression slope b of the length–weight relationship was equal to 3.04. The mean (±SD) condition factor for all fish was 1.23 ± 0.13. The condition factor was different in the length groups, with the highest (1.32 ± 0.13) and lowest (1.12 ± 0.20) values recorded in length groups 100–110 and <30 cm TL, respectively. The highest and lowest condition factors were recorded between January and March, respectively. The length–weight relationship and condition of Nile perch in Lake Victoria have deteriorated greatly, this finding being linked to the reduction of its prey species in the lake.     

Mechanism and Kinetics of Aluminum Nitride Powder Degradation in Moist Air

Aluminum nitride (AlN) powders manufactured via three major commercial processes, namely, chemical vapor deposition from triethyl aluminum, carbothermal reduction and nitridation of alumina, and direct nitridation of aluminum, were exposed to moist air at room temperature to investigate the degradation mechanism and kinetics. In the degradation, the powders were initially hydrolyzed to amorphous aluminum oxyhydroxide, which subsequently transformed into mixtures of crystallized aluminum trihydroxide (Al(OH)₃) polymorphs, i.e., bayerite, nordstrandite, and gibbsite, forming agglomerates around the unreacted AlN. The data were fitted by using the unreacted-core model. Three stages were found in the degradation: the stage of an induction period at the beginning, followed by a stage of fast hydrolysis with the chemical reaction being rate controlling, and finally, with gradual closing of pores in the structure of Al(OH)₃ around AlN, changing to a stage of slow hydrolysis that was controlled by mass diffusion through Al(OH)₃. The existence of an induction period was attributed to slow hydrolysis of the surface oxide/oxyhydroxide layer. The powder produced by the carbothermal process showed the longest induction period, which was attributed to its surface structure being different from other powders.     

Electrode reaction of the Np3+/Np couple at liquid Cd and Bi electrodes in LiCl–KCl eutectic melts

The electrode reactions of the Np³⁺/Np couple at liquid Cd and Bi electrodes were investigated by cyclic voltammetry at 723, 773 and 823 K in the LiCl–KCl eutectic melt. It was found that the diffusion of Np³⁺ in the salt phase was the rate-determining step in the cathodic reaction when the concentration of NpCl₃ was less than about 1 wt % and the liquid Cd or Bi phase was not saturated with Np. The redox potentials of the Np³⁺/Np couple at the liquid Cd electrode at 723, 773 and 823 K were observed to be more positive than those at the Mo electrode by 0.158, 0.140 and 0.126 V, respectively. The potential shift results from a lowering of the activity of Np in the Cd phase according to the formation of the NpCd₁₁ alloy at 723 K and NpCd₆ at 773 and 823 K. The redox potentials of the Np³⁺/Np couple at the liquid Bi electrode at 723, 773 and 823 K were more positive than those at the Mo electrode by 0.427, 0.419 and 0.410 V, respectively, which is attributable to a lowering of the activity of Np in the Bi phase due to the formation of NpBi₂.     

In situ polarized total-reflection fluorescence X-ray absorption near-edge structure spectroscopy for the analysis of oriented structure of vanadium oxides on ZrO2(100)

The oriented structure of the exposed V=O bond of vanadium oxides on ZrO₂(100) was studied by in situ polarized total-reflection fluorescence X-ray absorption near-edge structure (XANES) spectroscopy. The pre-edge peak intensity of s-polarized XANES was half the intensity of the p-polarized one. Moreover, both pre-edge peaks decreased in a similar way and eventually became zero by the reaction of V=O bonds with NH₃ at 423 K, suggesting that all of the observed V=O bonds behaved as active sites. The present technique suggests that the exposed V=O bonds are oriented to a 45°-direction from the normal to the ZrO₂(100) surface.