Design of stabilized laser for optically pumped atomic frequency standards

The influence of a stabilized laser's fluctuations in an optically pumped atomic frequency standard is considered. It is important to use a laser with narrow linewidth and select the modulation frequency where the laser's free‐running frequency fluctuation at twice the modulation frequency is the lowest. Employing these considerations, the stabilized laser for our optically pumped cesium beam frequency standard is designed. © 2001 Scripta Technica, Electr Eng Jpn, 136(2): 31–37, 2001     

Reactive processing of polymer blends: Analysis of the change in morphological and interfacial parameters with processing

The change in morphology and interface quantities have been analyzed for an immiscible polymer blend during reactive processing. A model polymer/polymer combination, hydroxy-terminated poly(ε-caprolactone)/liquid rubber with α, ω-carboxy groups, was employed. The blend was subjected to light scattering measurements, ellipsometry, and gel permeation chromatography (GPC). Size reduction of the dispersed phase during processing was followed by a systematic decrease in the correlation distance ζ and an increase in the specific interfacial area Ssp, both by the Debye-Bueche plot of light scattering profiles. Also observed was the time variation of the volume fraction of interface V_λ estimated as a product of the Ssp and the interfacial thickness by ellipsometry. The changes in ζ, Ssp, and V_λ with processing were accelerated when a coupling agent,γ-aminopropyltriethoxysilane (APS), was added. The amount of block copolymer formed in-situ in the APS-loaded system was estimated by GPC with RI and UV detectors. For the size reduction kinetics in both APS-loaded and -unloaded systems, Rittinger's law was found to be applicable.     

Heat capacities of NpN and AmN

The heat capacities of NpN and AmN were determined with the drop calorimetry method. The NpN and AmN samples were prepared by the carbothermic reduction of the respective dioxides. The heat capacity of NpN obtained was in good agreement with the reported values in the temperature range from 334 to 1067 K, which was close to those of UN and PuN. The heat capacity of AmN was obtained experimentally for the first time, which was slightly smaller than those of UN, NpN and PuN in the temperature range from 354 to 1071 K.     

Effects of seasonings on physical properties and MRI T2 map of cooked spaghetti

The effect of seasonings on the texture of cooked spaghetti was examined by sensory and shearing tests. Spaghetti tossed with sucrose, trehalose, salt, and monosodium glutamate and their mixture retarded deterioration of the firmness of spaghetti strands. To investigate the penetration of water and seasonings, maps of spin–spin relaxation time and their profiles from the center to the surface of a spaghetti strand were acquired by magnetic resonance imaging. The homogenization of moisture distribution in cooked spaghetti during holding was delayed temporarily by salt owing to a back current caused by the gradient of salt content on the surface immediately after tossing. Monosodium glutamate rapidly penetrated into spaghetti strands and caused water T₂ decrease possibly owing to the decreased mobility of water molecules in starch gel, whereas the sweeteners hardly altered the T₂ maps. Salt and monosodium glutamate are considered to retard more effectively the deterioration of firmness of spaghetti.     

Real-time monitoring system of tool breakage using Kalman filtering

In this paper, a real-time monitoring system of tool breakage, which measures the cutting torque from the spindle motor current, is described. The system uses an auto-regressive (AR)-model which is adapted for the measured signal using the Kalman filtering technique. The tool breakage is detected by monitoring the residual, that is, the deviation of the observed signal from the estimated value obtained by the AR-model. Additional processing of the residual is introduced to discriminate the signature of tool breakage from the effect caused by the marked change in the cutting condition. To reduce the computation time, the fast calculation algorithm is adopted for estimating the coefficient vector of the AR-model. The monitoring experiment has proven the effectiveness of the system in a milling operation.     

Loop recovery via ℋ︁∞-modified complementary sensitivity recovery for non-minimum phase plants

In order to recovery robust stability of a desirable state feedback system by output feedback, the desirable complementary function is approximated by a modified complementary function of the output feedback system by solving an ??^∞ norm-minimization problem. The modified complementary function is obtained by getting rid of non-minimum phase factors from the complementary function. Numerical examples show the superiority of this method to LQG/LTR method and other methods.     

Beta-decay half-lives calculated on the gross theory

Beta-decay half-lives have been calculated by the use of the gross theory which was formulated by Takahashi, Yamada, and Koyama. Both allowed and first-forbidden transitions have been taken into account, and consideration also has been given to the possibility that all the transitions to the levels near the ground states may be highly forbidden. The Q-values used in the calculation have been taken from the mass formula of Myers and Swiatecki. The calculated half-lives are shown in the PLOTS together with the experimental data and the Q-values. The PLOTS cover all the isotopes between the proton-drip and neutron-drip lines with Z = 3 to Z = 100.     

Irrigation

This paper provides an overview of the main features of irrigation in Japan, and the issues it raises, rather than an exhaustive survey of the subject. The authors’ remarks concentrate on irrigation for rice cultivation, since irrigation for non‐paddy crops is not widely developed and claims a very minor share of the country's water resources. The main components of the water requirements of rice irrigation are identified, and then the composition and functions of farmers’ irrigation associations, or more correctly ‘land improvement districts’, are described.