• Journal of Biosystems Engineering
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• v.42 no.3
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• pp.199-216
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• 2017

Purpose: This study reviewed the major nondestructive measurement techniques used to assess internal properties of agricultural materials that significantly influence the quality, safety, and value of the products in markets. Methods: Imaging technologies are powerful nondestructive analytical tools that possess specific advantages in revealing the internal properties of products. Results: This review was exploring the application of various imaging techniques, specifically, hyperspectral imaging (HSI), magnetic resonance imaging (MRI), soft X-ray, X-ray computed tomography (XRI-CT), thermal imaging (TI), and ultrasound imaging (UI), to investigate the internal properties of agricultural commodities. Conclusions: The basic instruments used in these techniques are discussed in the initial part of the review. In the context of an investigation of the internal properties of agricultural products, including crops, fruits, vegetables, poultry, meat, fish, and seeds, various extant studies are examined to understand the potential of these imaging technologies. Future trends for these imaging techniques are also presented.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.3-3
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• 2002

Many studies on crystal growth mechanisms of the hen egg-white lysozyme protein crystals have mainly performed by optical microscopy and atomic force microscopy (AFM). As results, two types of growth mechanisms, which are a two-dimensional nucleation mechanism and a spiral growth mechanism, were identified. However, there was no direct evidence of grown-in screw dislocations at the spiral sites. We first observed the screw dislocations in tetragonal lysozyme crystals using synchrotron X-ray topography. In addition, to confirm the characteristics of dislocations, we have observed some elastic constants in lysozyme crystals in terms of the sound velocity measurement by pulse echo methods. Tetragonal hen egg-white lysozyme crystals were grown by the concentration gradient method. The crystals were grown in test tubes, with an inner diameter of 8 ㎜ and 80 ㎜ in length, held vertically. The test tubes were kept at 23C for 2 weeks. The maximum size of crystals were 3×3×4 ㎟. The high quality crystals were examined by Laue topography with a water filter using synchrotron radiation. Figure is a X-ray topograph. Several straight screw dislocations were observed. We also determined Burgers vector to be a [110] direction. The measurement of sound velocity was performed by the digital signal processing method. the crystals were placed in stainless steel vessel, which was filled with lysozyme solution used for crystal growth. We observed the longitudinal sound velocity along the [110] direction in the tetragonal is obtained to be 1817 ㎧. Therefore, Young modulus and shear modulus were evaluated to be 2.70 Gpa and 1.02 Gpa, respectively, if we assumed Poisson ratio is 0.33. These results will be discussed at the meeting.

• Journal of Magnetics
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• v.14 no.2
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• pp.62-65
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• 2009

The multiferroic $BiFeO_3$ has been investigated extensively in both thin film and ceramic form. However, the synthesis of a perfect sample with high resistivity is a prerequisite for examining its properties. This paper reports the synthesis of multiferroic $BiFeO_3$ along with its structural, electrical and magnetic properties in ceramic form. Polycrystalline ceramic samples of $BiFeO_3$ were synthesized by solid-state reaction using high purity oxides and carbonates. The formation of a single-phase compound was confirmed by x-ray diffraction and its lattice parameters were determined using a standard computer program. The microstructural studies and density measurement confirmed that the prepared samples were sufficiently dense for an examination of its electrical and magnetic properties. The dc electrical conductivity studies show that the sample was resistive with an activation energy of ${\sim}0.81\;eV$. The magnetization measurement showed a linear ($M{\sim}H$) curve indicating antiferromagnetic characteristics.

• Journal of Welding and Joining
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• v.14 no.4
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• pp.43-52
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• 1996

The plasma sprayed Cr$_{2}$C$_{2}$-NiCr coatings are widely used as wear-resistant and corrosion-resistant materials. The mechanical properties of the plasma sprayed Cr$_{2}$C$_{2}$-NiCr coatings were examined in this study. The distribution of the residual stress with the coating thickness was also examined by X-ray diffraction method. The pore in the coatings could be classified into two types ; one is the intrinsic pore originated from the spraying powder, the other is the extrinsic pore formed during spraying. During the tensile adhesion test, the fracture occurred at the interface of top coat and substrate or top coat and bond coat depending on the existence of bond coat. It was found that the compressive residual stress near the interface decreased with the increase of the top coat thickness. The tensile adhesion strength of the coating without bond coat was higher than that with bond coat, because the coating with bond coat has higher horizontal crack density near the interface between bond coat and top coat.

• Journal of Magnetics
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• v.8 no.4
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• pp.149-152
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• 2003

The electronic structure of Mn12-Ac molecular magnet has been investigated using synchrotron radiation. The valence-band photoemission spectroscopy (PES) measurement reveals that Mn 3d states are located near the top of the valence band. The trend in the measured valence-band PES spectra is found to be consistent with that in the calculated local density of states. The Mn 2p x-ray absorption spectroscopy (XAS) measurement provides evidence for the Mn$^{3+}$-Mn$^{4+}$ mixed-valent states.

• Journal of the Korean Vacuum Society
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• v.5 no.1
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• pp.54-61
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• 1996

Indium-tin oxide (ITO) films were deposited on the glass substrate by the reactive -ionized cluster beam deposition(ICBD) method. In the oxygen atmosphere, indium cluster formed through the nozzle is ionized by the electron bombardment and is accelerated to be deposited on the substrate. And tin is simultaneoulsy evaporated from the boron-nitride crucible. The chracteristics of films were examined by the X-ray photoelectron spectroscopy(XPS), glancing angle X-ray diffractrion(GXRD) and the electrical properties. were measured by 4-point-probe and Hall effect measurement system . From the XPS spectrum , it was found that indium and tin atoms combined with the oxygen to form oxide$(In_2O_3, SnO_2)$. In the case of films with high tin-concentration, the GXRD spectra show that the main $In_2O_3$ peak of (222) plane, but also sub peaks((440) peak etc.) and $SnO_2$ peaks were detected. From that results, itis concluded that the heavily dopped tin component (more than 14 at. %) disturbs to form $In_2O_3$(222) phase. Four-point-probe and Hall effect measurement show that, in the most desirable case, the transmittance of the films is more then 90% in visible range and its resistivity is $$\rho$=3.55 \times10^{-4}\Omega$cm and its mobility is $\mu$=42.8 $\textrm{cm}^2$/Vsec.

• Journal of the Korean Society of Radiology
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• v.1 no.1
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• pp.11-16
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• 2007

In this study, we have performed contrast-detail analysis for an amorphous selenium(a-Se) based digital X-ray imaging system by using a contrast-detail phantom(CDRAD 2.0) to test its low contrast performance. The X-ray imaging system utilizes an 500-mm-thick a-Se semiconductor X-ray absorber coated over an amorphous silicon(a-Si) TFT(thin-film transistor) detector matrix with a $139mm{\times}139mm$ pixel size and a $46.7cm{\times}46.7cm$ active area. In the measurement of contrast-detail curves we first acquired X-ray images of the CDRAD 2.0 phantom at given test conditions(i.e., 40, 50, 60, 70, 80 kVp, and 16 mA.s), and then evaluated the contrast-detail characteristics of the imaging system from each phantom image by using an image quality factor called the image-quality-figure-inverse(IQFinv). The IQFinv values for the imaging system gradually improved with the photon fluence, indicating the improvement of image visibility: 24.4, 35.3, 39.2, 41.5, and 43.4 at photon fluences of $1.8{\times}105$, $5.9{\times}105$, $11.3{\times}105$, $19.4{\times}105$, and $29.4{\times}105$ photons/$mm^2$, respectively.

• Journal of the Korean earth science society
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• v.27 no.5
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• pp.521-527
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• 2006

The EPMA analysis for CHIME dating requires standard materials, which include nuclear fuel materials that are rare and sensitive to handle. Any laboratory that does not meet these standards has had difficulties adopting the CHIME dating method. We have developed a working standard technique for CHIME dating to prepare standard materials without use of nuclear fuel materials. Mineral samples, such as small pieces of monazite that are homogeneous in X-ray intensities, are calibrated using well-characterized primary standards in one laboratory. Once this procedure is done, they can be readily usable as working standards in the other laboratories, only with measurement of X-ray intensities. This method is applicable in preparing standard materials for both chemical compositions and determination of X-ray interference correction factors, and it is independent from chemical composition of mineral standard.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.397-400
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• 2014

This study purpose is to know about the effect of Cobb's angle of scoliosis patient by Pilates ecercise. It was executed for prove this exercise with Pilates Postural Correct Exercise(PCE), Spine Stretching Exercis(SSE), Muscle Strengthing Exercise(MSE). PCE is useful for unbalanced muscle energy and SSE gives relax for hypertensioned muscles and MSE is correcting balance for prime mover and secondary mover and so it will be recovery for elasticity and flexibility of paraspine muscles. The method study was proved with a Cobb's angle measurement of Lumbar spine by X-ray test before and after. As a result for the test, Cobb's angle by X-ray it shows reduced about 5 degree in statistics(p=0.005). And so It shows the Pilates exercise gives reduce for Scoliosis.

• Journal of the Korean Society for Heat Treatment
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• v.30 no.5
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• pp.215-221
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• 2017

The effect of austenitizing temperature on the degree of carbides re-solutionizing, mean graine size, hardness and the volume fraction of retaind austenite ($V_{\gamma}$) etc., has been studied by means of metallography, X-ray diffractometry and hardness measurement in STD 11 tool steel. As austenitizing temperature increases, the amount of alloying elements which is re-dissolved into matrix increases, resulting in increase of $V_{\gamma}$, due to the chemical stabilization of austenite. The Vickers hardness value decreases with increasing austenitizing temperature, which is attributed to grain size as well the volume fractions of $V_{\gamma}$ and carbides. Theoretical diffraction intensity of (200) ${\alpha}^{\prime}$, (211) ${\alpha}^{\prime}$ (200) ${\gamma}$ and (220) ${\gamma}$ peaks obtained by $CuK_{\alpha}$ chracteristics X-ray (${\lambda}=0.15429nm$) was calculated, and quantitative analysis of $V_{\gamma}$ could be carried out by X-ray diffraction method. The resultant value is well coincided with the value obtained by image analysis method. When the quenched specimen is tempered above $200{\sim}400^{\circ}C$ for 30 min, the transition carbides i.e., MC and $M_2C$ in the size of about 20 nm begin to precipitate at $300^{\circ}C$.