Stabilization of a non-linear distributed parameter vibratory system

The feedback stabilization problem for a non-linear elastic distributed parameter system including a destabilizing effect is studied. The model is formulated as an evolution equation in a Hilbert space. Semigroup theory is used to investigate an initial value problem for the equation. Moreover, a control system with a finite dimensional controller is constructed. It is then proved that the state of the overall system converges to zero with a desirable exponential decay rate as time tends to infinity.     

Characterization of the cobalt component in the positive- electrode material of a nickel metal hydride battery using extended X-ray absorption fine structure

Abstracts are not published in this journal     

Potentials of GHG reductions from wastewater treatment for the CDM

The study aims to evaluate the potential of GHG (greenhouse gas) reductions by installing an anaerobic digester in a wastewater treatment facility in Southeast Asia. Then the break-even point of additional investment to reduce GHG is obtained by exchanging carbon price as emissions credits. In the project scenario, the wastewater treatment system has the digester, where methane (biogas) is produced and recovered. Compared with the baseline scenario, the biogas has calorific value to produce heat and electri...     

Heat and Moisture Transfer in Composite Food—Theoretical Analysis of Influence of Surface Conductance and Component Arrangement

Heat and moisture transfer in composite bodies undergoing drying was simulated using a previously developed mathematical model which included the chemical potential of moisture as a mass transfer potential. Composite bodies included layered cylinders and concentric spheres consisting of a starch granule hydrate (H) and a hydrate of starch granules-sucrose 3:l mixture (S). The influence of the following factors on heat and moisture transfer was examined: convective surface mass transfer conductance, initial moisture, and component arrangement. The three factors significantly influenced moisture transfer white they had slight influence on heat transfer. Overall drying rate of each composite body was infhrenced interactively by moisture fluxes, which were caused by a surrounding drying medium and by a mass transfer potential difference across the interface of H and S.     

A Verification of Estimation Accuracy of Lightning Current Waveform and Charge Transfer from Measured E‐Field Waveform

To establish effective countermeasures on power facilities against lightning damage, it is necessary to clarify the lightning characteristics such as current parameters at the area of interest. In order to collect lightning current parameters effectively, the authors have observed electric and magnetic field waveforms simultaneously at south Kyushu, where the lightning flash density in summer is high. Based on observed electric field waveforms, the lightning current parameters have been estimated by adopting the Diendorfer–Uman model (DU model) as the return‐stroke model. In this paper, the accuracy of the estimated return‐stroke current waveform is verified by comparison with directly measured return‐stroke current waveform, along with the accuracy of the estimated charge transfer from the electric field waveform measured with a slow antenna.     

COLOR CHANGES CAUSED BY SPECIFIED CHANGES IN THE ILLUMINANT

Nonlinear optimization techniques can be used to calculate the theoretical limits of color changes that can occur when the spectral power distribution of the illuminant is permitted to deviate from that of the standard illuminant by specified amounts. The study has a direct bearing on the problem of specifying tolerances for illuminants relative to a given standard illuminant used in colorimetry.     

Development of Control Method for Outer‐Rotor Spherical Actuator

Conventional multi‐degree‐of‐freedom drive systems need many single‐degree‐of‐freedom actuators, but this makes the structure larger and heavier. The development of a spherical actuator should reduce the number of actuators, but the low torque and narrow rotation range are still problems. We developed a 2‐degree‐of‐freedom spherical actuator with an outer rotor that can produce a higher torque and wider rotation angle. In this paper, we propose a control method; we confirmed its usefulness by performing dynamic analysis using the three‐dimensional finite element method and by taking measurements with a prototype.     

Computerized Model for Strain-Stress Analysis of Food Undergoing Simultaneous Heat and Mass Transfer

A computerized method was developed for simulating transient state heat and moisture transfer and stress distribution in axisymmetric food undergoing drying process. For this development, a simultaneous heat and moisture transfer model was coupled with the virtual work principle applicable to a body undergoing volumetric changes. The developed method was verified by comparing experimental results with those predicted. Experimental results were obtained by drying cylindrically formed samples of hydrated starch granules. They included central temperature, average concentration histories and photographically observed internal crack formations.     

RAPID MESOCARP CELL ELONGATION ENHANCES GUMMING SYNDROME IN JAPANESE APRICOT (PRUNUS MUME SIEB. ET ZUCC.) FRUIT

ABSTRACT

Japanese apricot (Prunus mume Sieb. et Zucc.) ‘Benisashi’ fruit tends to show the physiological disorder of a gumming syndrome, while the fruit known as ‘Nanko’ rarely show this. The accumulated gum becomes a solid gel during the processing period and the commercial value of the mume pickle is consequently decreased. In the present experiment, gum accumulation in the mesocarp tissue and the cell size of the tissue during fruit growth were observed in the two cultivars. In mid‐May, the initiation of the gum duct was observed in vascular bundles in the mesocarp tissue of the two cultivars and plant gum was then observed to accumulate in the duct. No difference in these phenomena was observed between the cultivars until late May. Thereafter, ‘Benisashi’ developed a gum lump visible to the naked eye during Stage III, while the gum lump of ‘Nanko’ did not develop to the visible size as shown in ‘Benisashi’; the lumps could not be confirmed with the naked eye until the mature stage. ‘Benisashi’ showed more rapid fruit growth compared with ‘Nanko’ during Stage III due to explosive mesocarp cell elongation close to the endocarp. Moreover, the rate of gumming fruit of ‘Benisashi’ was higher in bigger fruits than smaller ones. These results indicate that the peculiar cell growth of ‘Benisashi’ fruit may accelerate gum lump formation.

PRACTICAL APPLICATIONS

Gumming syndrome affects the quality of mume pickle. In this experiment, we investigated the mechanisms of gum accumulation in fruit flesh. ‘Benisashi’, which frequently shows the gumming syndrome, presented rapid inner mesocarp cell growth on fruits developing Stage III. This peculiar cell growth may accelerate gum lump formation. Therefore, we have to prevent the cultivational misconduct that induces rapid fruit growth in this period to suppress the gumming syndrome and to increase the commercial value of mume pickle. Moreover, this knowledge is also important in order to breed the new cultivars which do not contain the gumming syndrome.