• Korean Journal of Crystallography
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• v.8 no.1
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• pp.20-25
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• 1997

Two experimental methods have been developed for high resolution measurement of x-ray scattering. The methods used were (1) an x-ray double crystal diffraction (DCD) spectrometer set-up and (2) an x-ray triple crystal diffraction (TCD) spectrometer set-up. With the DCD arrangement of Si(511)-sample(hkl), rocking curves have been plotted for Si (333), Si(004) and GaAs(004). Also, with the TCD arrangement of Si(111)-Si(111)-Si(511)-sample(hkl) including monolithic monocro-collimator and $K_{\alpha1}$ selector, rocking curves have been plotted for Si(333), Si(004) and GaAs(004). The results of FWHM by DCD and TCD set-up have been compared each other and discussed. The reflection topographs (004) and (115) in an $In_{0.037}Ga_{0.0963}As/GaAs$ sample have been obtained by DCD set-up.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.201-205
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• 2010

Most of iodine was captured by the block when NaI solution flowed through a bentonite block sorbed silver to retard the migration of iodine released from high-level radioactive wastes. In order to understand in detail the mechanism for the retardation of the iodine by the silver ion, X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) spectra of the silver sorbed bentonite before and after the contact with iodide were compared with those of AgO, $Ag_2O$ and AgI as references. This examination suggests that the silver ion sorbed on the bentonite is desorbed, and then it retards the migration of iodine by forming the cluster of AgI precipitate.

• Journal of Surface Science and Engineering
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• v.32 no.3
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• pp.239-243
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• 1999

At Present, 200mm wafer technology is being applied for commercial fabrications of 64, 128, and 256 M DRAM devices, and 300mm technology will be evolved for 1G DRAM devices in the early 21th century, recognizing limitations of several process technologies. In particular recognition has been realized in harmful effects of surface contamination of trace metals introduced during devicing processes. Such a guide line for surface metal contamination has been proposed as 1E9 and 1E10 atoms/$\textrm{cm}^2$ of individual metal contamination for wafering and devicing of 1G DRAM, respectively, and so its measurement limit should be at least 1E8 atoms/$\textrm{cm}^2$. The detection limit of present measurement systems is 2E9 atoms/$\textrm{cm}^2$ obtainable with TRXFA(Total Reflection X-Ray Fluorescence Analysis). TRXFA is nondestructive and the simplest in terms of operation, and it maps the whole wafer surfaces but needs detection improvement. X-Ray intensity produced with synchrotron accelerator is much higher than that of conventional X-ray sources by order of 4-5 magnitudes. Hence theoretically its reactivity with silicon surfaces is expected to be much higher than the conventional one, realizing improvement of detection limit. X-ray produced with synchrotron accelerator is illuminated at a very low angle with silicon wafer surfaces such as 0.1 degree and reflects totally. Hence informations only from surface can be collected and utilized without overlapping with bulk informations. This study shows the total reflection phenomenon and quantitative improvement of detection limit for metallic contamination. It is confirmed that synchrotron X-ray can be a very promising alternative for realizing improvement of detection limit for the next generation devices.

• Korean Journal of Metals and Materials
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• v.48 no.8
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• pp.705-716
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• 2010

Effects of specimen thickness and notch shape on fracture mode appearing in drop weight tear test (DWTT) specimens of API X70 and X80 linepipe steels were investigated. Detailed microstructural analysis of fractured DWTT specimens showed that the fractures were initiated in normal cleavage mode near the specimen notch, and that some separations were observed at the center of the fracture surfaces. The Chevron-notch (CN) DWTT specimens had broader normal cleavage surfaces than the pressed-notch (PN) DWTT specimens. Larger inverse fracture surfaces appeared in the PN DWTT specimens because of the higher fracture initiation energy at the notch and the higher strain hardening in the hammer-impacted region. The number and length of separations were larger in the CN DWTT specimens than in the PN DWTT specimens, and increased with increasing specimen thickness due to the plane strain condition effect. As the test temperature decreased, the tendency to separations increased, but separations were not found when the cleavage fracture prevailed at very low temperatures. The DWTT test results, such as upper shelf energy and energy transition temperature, were discussed in relation with microstructures and fracture modes including cleavage fracture, shear fracture, inverse fracture, and separations.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3335-3346
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• 2024

Due to the radiation released by commonly used isotopes, many nuclear, medical, and industrial facilities require proper radiation shielding. In this work, distinct copper borate glasses intercalated with varied aluminum and vanadium oxide (Al₂O₃ and V₂O₅) content have been synthesized and used against radiation (gamma rays and fast/thermal neutrons). The different percents were as follows: [60% B₂O₃ + 35% CuO + (5-x)% Al₂O₃ + xV₂O₅], where x = 0, 1, and 2.5 wt.%, which was coded as BCu(5-x)Al:xV. The synthesized glass samples were characterized using Fourier transforms, infrared, and X-Raydiffraction analysis. Experimentally, the radiation shielding possessions of the samples were established using an HPGe detector at the gamma energy lines 0.356 MeV, 0.661 MeV, 1.173 MeV, and 1.332 MeV. Also, the prepared glasses were investigated theoretically using the Monte Carlo code (MCNP5) at photon energies of 0.015-15 MeV. Also, the fast and thermal neutron macroscopic effective removal cross-sections were calculated using MRCsC and JANIS-4.1 software, respectively. The prepared sample BCu2.5Al:2.5V, which has a vanadium and aluminum content of 2.5%, has the highest linear attenuation coefficient as well as the highest removal cross-section for fast, and thermal neutrons.

• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.490-497
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• 1990

Two synthetic routes for the 1,4-diboracyclohexene-2 ring 8 have been developed. Method i) starts with 1,2-bis(dichloroaluminyl)ethane, in which the AlCl$_2$ group is replaced by BCl$_2$. Exchange of the chlorine with BI$_3$ in 1,2-bis-(dichloroboryl)ethane yields the corresponding iodo compound, which reacts with the alkynes to heterocycles 8a, b in good yield. In method ii) B$_2$Cl$_4$ is added to alkenes, replacement of chlorine with BI$_3$ yields the bis(diiodoboryl)ethane derivatives which undergo redox reactions with alkynes to give 8c, d. The diiodo derivative 8a forms the pyridine adduct 9a, and reacts with ether to give the ethoxy derivative 8f. 8a-d react with AlMe$_3$ to yield the corresponding dimethyl derivatives 8g-j, which give unstable radical anions when treated with potassium in THF. The ESR parameters are reported. In electrochemical experiments irreversible reductions of 8g-j are observed. 8g-j react with (C$_5$H$_5$)Co(C$_2$H$_4$)$_2$ to give the intermediate 16 VE complexes (C$_5$H$_5$)Co(8), in which C-H activation occurs with formation of the corresponding red 1,4-diboracyclohexadiene complexes 10. The X-ray structure analyses of 10h and 10j are reported.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.4
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• pp.139-146
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• 2010

Objectives : To compare the differences between the symptoms and the findings of MRI(magnetic resonance imaging) and x-ray, we studied the patients with neck pain or radiating pain, which has been diagnosed as cervical herniated disc recently. Methods : We randomly selected among the 143 patients with x-ray and cervical spine(C-spine) MRI films who have visited Ja-seng hospital with neck pain and neck and radiating pain from April 1 of 2010 to May 1. We used SPSS 13.0 for windows in analyzing statistical data of study results and the level of significance was below 0.05. Results : 1. There were no significant differences between the presence of radiating pain and the amount of cervical herniation(p>0.05). 2. If the finding of a x-ray showed narrowing, based on MRI findings, the amount of herniation was more severe(p>0.05). 3. There were no significant differences between the presence of radiating pain and the findings of x-ray(p>0.05). 4. Among the 143 cases, which showed findings beside HIVD(herniation of intervertebral disc) were 13 cases. 88 cases of straightening(61.5%). 78 cases of uncovertebral joint arthrosis(54.5%). 25 cases of stenosis(17.5%), 13 cases of retrolisthesis(9.1%), 8 cases of osteophyte(6.6%), 4 cases of spondylolisthesis(2.8%), 2 cases of hemangioma(1.4%), 3 cases of OPLL(ossification of posterior longitudinal ligament)(2.1%), 2 cases of block vertebrae(1.4%), 2 cases of spondylitis(1.4%), 1 case of kyphosis(0.1) and 1 case of ligamentum flavum hypertrophy(0.1%). Conclusions : The findings from this study suggest that there was no relation between radiating pain and radiological result. On the other hand, diagnosis of x-ray and MRI showed significant relevance. The narrower disc space there were, the severer the state of herniation there existed.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.401-405
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• 2008

This study was conducted to estimate the control thresholds (CTs) of imported cabbage worm, Artogeia rapae L., injuring Chinese cabbage. The second instar larvae of A. rapae were inoculated with five density levels on each Chinese cabbages transplanted three weeks earlier under greenhouse condition, and checked injury rates after allowing their feeding for one week and two weeks, respectively. The average leaf area consumed by single larvae was 657.7 $mm^2$ in plots inoculated at three weeks after transplanting (WAT) and 2495.8 $mm^2$ in plots at 6-WAT, respectively. In the field experiment, different numbers of A. rapae ranged from one to seven larvae were inoculated on 20 plants. The percent yield reduction (Y) of Chinese cabbage infested by different densities of A. rapae (X) for a three-week period was estimated by the following equation; (1) Y=1.764X-0.3049 ($R^2$=0.9901) in plots inoculated at 3-WAT; and (2) Y=1.0305X-0.2976 ($R^2$=0.9398) in plots inoculated at 6-WAT. Based on the relationships between the densities of A. rapae larvae and the yield index of Chinese cabbage, the number of second instar larvae which caused 5% loss of yield (gain threshold proposed by Japan), was estimated as 3.0 per 20 plants for the 3-WAT and 5.1 for the 6-WAT.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.269-276
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• 2015

This paper proves the Erd$\ddot{o}$s-Faber-Lov$\acute{a}$sz conjecture of the vertex coloring problem, which is so far unresolved. The Erd$\ddot{o}$s-Faber-Lov$\acute{a}$sz conjecture states that "the union of k copies of k-cliques intersecting in at most one vertex pairwise is k-chromatic." i.e., x(G)=k. In a bid to prove this conjecture, this paper employs a method in which it determines the number of intersecting vertices and that of cliques that intersect at one vertex so as to count a vertex of the minimum degree ${\delta}(G)$ in the Minimum Independent Set (MIS) if both the numbers are even and to count a vertex of the maximum degree ${\Delta}(G)$ in otherwise. As a result of this algorithm, the number of MIS obtained is x(G)=k. When applied to $K_k$-clique sum intersecting graphs wherein $3{\leq}k{\leq}8$, the proposed method has proved to be successful in obtaining x(G)=k in all of them. To conclude, the Erd$\ddot{o}$s-Faber-Lov$\acute{a}$sz conjecture implying that "the k-number of $K_k$-clique sum intersecting graph is k-chromatic" is proven.

• Journal of Nutrition and Health
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• v.48 no.5
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• pp.398-406
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• 2015

Purpose: In the present study, we aimed to evaluate the effect of sucrose containing 2 different levels of xylooligosaccharide on the glycemic index (GI) and blood glucose response in healthy adults. Methods: Healthy adults (4 male participants and 6 female participants, n = 10) were randomized to receive glucose, sucrose, sucrose containing 7% xylooligosaccharide active elements (Xylo 7), or sucrose containing 10% xylooligosaccharide active elements (Xylo 10). Each participant was administrated one of these materials once a week for 8 weeks and an oral glucose tolerance test was performed. Results: We found a reduction in the glycemic response to sucrose that included xylooligosaccharide active elements (Xylo 7 and Xylo 10). The glycemic indices of sucrose, Xylo 7 and Xylo 10 were 68.9, 54.7, and 52.5, respectively. The GI values of Xylo 7 and Xylo 10 were similar to that of foods with low GI. The percentage reduction of GI value caused by sucrose containing xylooligosaccharide active elements was significantly different and dose-dependent as compared to that caused by sucrose alone (p < 0.05). The reduction in the glycemic response to Xylo 7 and Xylo 10 was 21% and 24%, respectively, as compared to the glycemic response to sucrose. The attenuation of the glycemic response to Xylo 10 tended to be higher than that for Xylo 7 when the percentage of body fat was increased. Conclusion: These results demonstrated that xylooligosaccharide active elements may be effective in protecting humans against overconsumption of sucrose.