[en] For the purpose of nondestructive determining of soil water content near the surface of a sandy field, a surface-type neutron moisture meter with the capability of making backscatter and direct transmission measurements was introduced. In this paper, the response on this surface-type neutron moisture meter at source positions of 0, 5, 10, 15, 20, 25, 30 cm was described by an experiment using dune sand with different water contents. To know how large the sphere of importance of a surface-type neutron moisture meter is, the influence of the presence of a paraffin mass on the count ratio was examined for the dune sand in the vertical and horizontal directions. In case of the backscatter method, the radius of the sphere of importance was obtained as the function of the volumetric water content. Furthermore, calibration curves of the surface-type neutron moisture meter for the source depths of 0, 5, 10, 15 cm were determined for a dune sand in a calibration vessel. Therefore, the utility of the calibration curves to measure the soil water content in a sandy field was discussed by the experiment with a relatively higher water content in a lysimeter during drainage and by core sampling with a relatively lower water content in an actual sandy field. As a result, it was recognized that the calibration curves for source depths of 5 and 10 cm could be practically used to monitor the soil water content near the surface in an actual sandy field within the measuring error of 1% by volume

No abstract available

[en] Following the 2002 Conference on Open Magnetic Systems for Plasma Confinement, a three times progress in the formation of ion-confining potential height is achieved in the hot-ion mode. The advance in the potential formation leads to a finding of remarkable effects of radially produced shear of electric fields dEr/dr on the suppression of not only coherent drift waves but turbulence-like fluctuations for the first time in GAMMA 10. Also, the progress in the potential formation is made in line with the extension of our proposed physics scaling of potential formation covering over representative tandem-mirror operational modes, characterized in terms of (a) a high-potential mode having kV-order plasmaconfining potentials and (b) a hot-ion mode yielding fusion neutrons with 10-20 keV bulk-ion temperatures (T_i)

[en] It is clear that ground conditions have a large effect on the thermal environment. Plant canopies have their own characteristic types of architecture and have a great influence upon the action and reaction processes occurring between plants and their environment through the modification and interception of fluxes of radiation, heat and mass. A numerical experiment was carried out to determine the diurnal changes occurring in soil and air temperatures near the ground surface covered by a plant. The model assumed that a canopy can be mathematically condensed into a single plane and treated as a single ‘big leaf’. The stomatal resistance was estimated by using the rectangular hyperbolic relationship between stomatal resistance and irradiance. Wind velocity, potential temperature and specific humidity values of 3.6m/s, 25°C and 0.0015 were applied respectively at the upper boundary (100 m), and a temperature of 25°C was specified for the lower boundary (-0.5m). All these conditions were kept constant throughout the simulation period. The analysis was performed on the basis of irradiant data obtained in Fukuoka City (latitude 33° 38'N) on 26 th July, 1978. The temperature profiles during daylight were characterized by curves with a maximum in the canopy layer. The temperature range on the soil surface was reduced owing to the effect of shading by the leaves. These phenomena make the formation of the thermal environment on a plant canopy extremely complex. In the case presented in this paper, the type of plant canopy investigated was similar to that of a soybean field with plants 1.00 m high, but the method could easily be adapted to simulate the thermal environment of a tall canopy, such as that in a forest. (author)

[en] Much of the work relating canopy temperature to crop water stress has been done in the U. S. A. The leaf-based measurements are time consuming when the fields of the size larger. The measurement of canopy temperature using infrared thermometer is the most promising approach to irrigation scheduling. In this paper, three indices were examined. The first index used only canopy-air temperature differentials. The second index used canopy-air temperature differentials and vapor pressure deficits. The third index used crop water stress index (CWS1). These three indices were evaluated the applicability to irrigation scheduling. The canopy temperature are simulated for progressive soil drying using the continuity equation for water flux in the soil-plant-atmosphere system. With this model, characteristic features of these three indices were mathematically examined

[en] A mirror magnetic field configuration (MFC) is studied in which a divertor is distributed axially using multipole coils. Both configurations of divertor and minimum-B are obtained in a mirror cell. Magnetohydrodynamic (MHD) instability of a mirror cell can be eliminated in this way. Concept of the design and properties of the MFC are discussed

[en] It is well known that leaf temperature rises with increased crop water stress. This phenomenon is recognized as having the potential to yield information on irrigation scheduling. In this study, infrared thermometry was used to measure crop temperature remotely. The errors in measurements derived from incoming long-wave radiation and leaf emissivity were experimentally evaluated in relation to the reliability of three types of water stress indices using leaf temperature as the parameter. From consecutive measurements of the crop-air temperature difference, obvious changes in daily pattern could be detected as soil water became limited. This result showed that the crop-air temperature difference, although a simple index, can be used in irrigation timing

[en] In tandem mirrors, electron cyclotron heating (ECH) is utilized for the formation of a thermal-barrier potential Φ_b in the barrier region and an ion confining potential Φ_c in the plug region. These regions and the central cell are directly connected through magnetic field lines; however, these are separated by the electrostatic potentials. In this paper, different shapes of electron velocity distribution functions f_e in these three regions have been reported using various X-ray observations. These in turn demonstrate the effects of electrostatic potentials on f_e. (author) 10 refs., 3 figs

[en] In this paper, recent upgraded experimental results in GAMMA 10 have been reported along with the recent extensions of important scaling laws; the scalings of potential formation and of energy confinement for both ions and electrons. Radial transport processes have also been investigated. (author) 6 refs., 3 figs

[en] The paper reports experimental results on potential formation and end plugging in the axisymmetrized tandem mirror GAMMA 10. The plugging at both ends has been achieved by a combination of neutral beams and gyrotrons. The presence of a plug potential with a thermal barrier in an axisymmetric mirror has been confirmed by direct measurement of the axial potential profile. Enhancement of axial particle confinement has been observed during the end plugging. Non-ambipolar radial transport has been greatly reduced in the axisymmetrized magnetic configuration. The potentials measured by beam probes and end loss analysers are 0.7, 0.4 and 1.1 kV in the central, barrier and plug regions, respectively. Strong end plugging is observed when the central-cell density is higher than the densities in the plug and the barrier, and the plug density remains higher than the barrier density. The plug electron temperature is higher than the central temperature. Hot electrons forming a football-shaped profile have been stably produced in the axisymmetric mirror. The beta value and the fraction of the hot electrons reach up to 5% and 0.8, respectively. Central-cell ion-cyclotron resonance heating can sustain a stable plasma with higher density and ion temperature when resonance surfaces exist in both the anchor and the central cells. (author)