[en] Dual-function interferometer is one of interferometers that have all features of ESPI (Electronic Speckle Pattern Interferometry) and shearography in one interferometer setup. The deformation of an object is directly obtained by ESPI while the slope of the deformation of an object is obtained by shearography. If the results of shearography are divided by shearing amount and integrated by numerical analyzing, then finally the reconstructed deformation of an object that is the same as the results directly obtained by ESPI can be measured by shearography. In this study, Cu-thin plate is used as specimen and its out-of-plane deformation is measured by ESPI and shearography setup of the dual-function interferometer. Each of the results obtained by ESPI and shearography is compared by using numerical integration to the result of shearography. From this study, it is confirmed that the reconstructed deformation results obtained by numerical integration good agrees with the results obtained by ESPI.

[en] This research develops the quantitative evaluation technique for inside delamination of impact-damaged composite plate by Electronic Speckle Pattern Interferometry(ESPI). ESPI, one of optical inspection methods is the technique of non-contact, non-destructive, whole-filed measurement and recently the method is applied for non-destructive inspection of composite plate structure. However, there is some difficult to evaluate defects quantitatively. In order to extract the quantitative results, 2D displacement distribution and the first derivates of displacement are analyzed and defect sizes in each interlaminar are estimated from defect size in front and backside. The proposed ESPI technique for quantitative evaluation of inside delamination in composite material structure is expected as the advanced non-destructive testing method with the merits of time-saving and non-contact

[en] Naturally occurring radioactive materials in geologic and building materials have been recommended or regulated in most countries. ²²⁶Ra, ²³²Th and ⁴⁰K are important radionuclides for building materials. Sometimes for radiation dosimetry, the activity of the radionuclides must be determined in short time. However, samples must be stored in measurement containers for 30 days for the determination of ²²⁶Ra in traditional gamma-spectrometry. In this study, pair measurement-gamma spectrometry (PM-GS) method was studied to determine rapidly ²²⁶Ra in geologic and building materials. The samples were measured two times within 7 days after sealing. The activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in geologic and building materials could be successfully determined within a week by using the PM-GS method. (author)

[en] Comprehensive numerical computations are made of a homogenous spin-up in a cylindrical cavity with a time-dependent rotation rate. Numerical solutions are acquired to the governing axisymmetric cylindrical Navier-Stokes equation. A rotation rate formula is Ω_f=Ω_i+ΔΩ(1-exp(-t/t_c)). If t_c is large, it implies that a rotation change rate is small. The Ekman number, E, is set to 10^-4 and the aspect ratio, R/H, fixed to 1. For a linear spin-up(ε<<1), the major contributor to spin-up in the interior is not viscous-diffusion term but inviscid term, especially Coriolis term, though t_c is very large. The viscous-diffusion term only works near sidewall. But for spin-up from rest, when t_c is very large, viscous-diffusion term affects interior area as well as sidewall, initially. So azimuthal velocity of interior for large t_c appears faster than that of interior for relatively small t_c. However, the viscous-diffusion term of interior decreases as time increases. Instead, inviscid term appears in the interior

[en] Comparison between strain values of plates measured by Electronic Speckle Pattern Interferometry(ESPI) method and strain gauge method is discussed. Unlike traditional method, such ax strain gauge and moire method, ESPI method requires no special surface preparations or attachments and can be measured in-plane displacement with non-contacting in real-time. In this study, specimens are loaded in parallel using tensile testing machine. In front of a specimen three strain gauges are bonded with 5 mm gap from edge of a specimen strain values are measured at each strain gauge position and compared. The results by ESPI method agree well with the result by strain gauge method.

[en] A continuous monitoring system (CMS) using an open loop equilibrator for assessment of ²²²Rn at the groundwater-surface water interface was developed and tested. For the characterization and validation of the system, three air loops (open loop, closed loop, and open bubble loop) were tested in relation to high and precise count rates, rapid response, and equilibration of radon. The water and air stream is fed to the equilibrator by an experimental setup with a commercial submersible water pump and the internal pump with built-in radon-in-air detector. Efficiency calibration of the CMS is done by simultaneous determination of a groundwater sample using liquid scintillation counting, and the RAD7 accessories RAD-H₂O, BigBottle RAD-H₂O. The higher count rates are provided by the closed loop. However, the open loop with bubbler (open bubble loop) provides the best precision count rates, rapid response, and equilibration time. The CMS allows radon determination in discrete water samples as well as continuous water streams. (author)