• Journal of Trauma and Injury
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• v.25 no.4
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• pp.241-246
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• 2012

Purpose: The objective of this study was to investigate the appropriateness of the cross table lateral cervical X-ray used in the emergency department for severely traumatized Korean patients. Methods: Patients visiting our institution from May 2011 to May 2012, who had injury severity score (ISS) > 15 and who received a cervical X-ray in the emergency department, were included in this study. Data including demographics, ISS score, GCS score, and place where the x-ray was taken were collected to evaluate their relationship with appropriate coverage of the cervical X-ray. The appropriateness of a cervical cross lateral view X-ray was evaluated using exposure of the basion, and the opisthion, as well as the distal level of exposure. Results: Fifty-two patients were included in this study. The identification rate of the basion was 79.2%, and the identification rate of the opisthion was 88.7%. Complete exposure of C7/T1 was accomplished in 3.8% of the patients. The ISS was higher for X-ray taken in the trauma bay, but the range of exposure showed no difference between the places where the X-rays taken. Patients who had exposure of C 5/6 or more had lower body weight and body mass index (BMI) compared with unexposed patients. Conclusion: In severely traumatized Korean patients, the adequacy of the cross table lateral cervical X-ray was inappropriate in most cases. No difference was observed in the exposure range between the places where the X-rays were taken, and patients with less exposure showed higher body weight and higher BMI.

• Nuclear Engineering and Technology
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• v.51 no.8
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• pp.2005-2012
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• 2019

This work investigated the radiation attenuation characteristics of three series of tellurite glass systems with the following compositions: 30PbO-10ZnO-xTeO₂-(60-x)B₂O₃ where x = 10, 30, 40, 50 and 60 mol%, xBaO-xB₂O₃-(100-2x)TeO₂ with x = 15-40 mol% and 50ZnO-(50-x)P₂O₅-xTeO₂, where x = 0, 10, .40 mol%. The results revealed that the attenuation parameters in all the samples decrease with increase in the energy, which implied that all the samples have better interaction with gamma photons at low energies and thus higher photon attenuating efficiency. From the three systems, the samples coded as PbZnBTe60, BaBTe70 and ZnPTe40 have the lowest half value layer values and accordingly have superior photon attenuation efficacy. The maximum effective atomic number values were found for energy less than 0.1 MeV particularly near the K-edges absorption of the heavy atomic number elements such as Te, Ba and Pb. At the lowest energy, the Z_eff values are found in the range of 62.33-66.25, 49.43-50.81 and 24.99-35.83 for series 1-3 respectively. Also, we found that the density of the glass remarkably affects the photon attenuation ability of the selected glasses. The mean free path results showed that the PbO-ZnO-TeO₂-B₂O₃ glass system has better radiation shielding efficiency than the glass samples in series 2 and 3.

• Korean Journal of Optics and Photonics
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• v.8 no.1
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• pp.1-6
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• 1997

The amplitude impulse S(x) of an interferometric optical imaging system for λ=193 nm(ArF laser) and NA=0.5 is derived for the pupil with superposed three Gauss pupils $A_1$($\omega$), $A_{2-}$($\omega$) and $A_{2+}$($\omega$). It is shown that FWHM of S(x) can be far less than the Rayleigh's criterion of resolution $\frac{1}{2}{\epsilon}_R$, where ${\epsilon}_R$ is equal to λ=193 nm in the present case of NA=0.5. The three Gauss pupils are provided in an optical system which consists of a Twyman-Green interferometer and an imaging system. The system is proposed and relevent optical components are discussed. Siloxane polymer is suggested for fabrications of amplitude modulation plates. In the present work, we assumed the system is free from aberration and linear. The case that the system has residual aberrations is important, and further work is necessary.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1759-1764
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• 2002

Two crystal structures of dehydrated $Ag^+-andTl^+$-exchanged zeolite X$Ag_{27}Tl_{65-}X\;and\;Ag_{23}Tl_{69-}X$have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21(1) $^{\circ}C(a=24.758(4)\AAa=24.947(4)$, ${\AA}respectively).$, Their structures were refined to the final error indices $R_1$=0.055 and $wR_2$=0.057 with 375 reflections, and $R_1$=0.057 and $wR_2$=0.057 with 235 reflections, respectively, for which I > $3\sigma(I).$ In the structure of $Ag_{27}Tl_{65-}X,\;27\;Ag^+$ ions were found at two crystallographic sites: 15$Ag^+$ ions at site I at the center of the hexagonal prism and the remaining 12$Ag^+$ ions at site II' in the sodalite cavity. Sixty-five $Tl^+$ ions were located at three crystallographic sites: 20$Tl^+$ ions at site II opposite single six-rings in the supercage, 18$Tl^+$ ions at site I' in the sodalite cavity opposite the D6Rs, and the remaining 27$Tl^+$ ions at site III' in the supercage. In the structure of $Ag_{23}Tl_{69-}X$, 23$Ag^+$ ions were found at two crystallographic sites: 15 at site I and 8 at site II'. Sixty-nine $Tl^+$ ions are found at four crystallographic sites: 24 at site II, 17 at stie I', and the remaining 28 at two III' sites with occupancies of 22 and 6.

• Fashion & Textile Research Journal
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• v.14 no.4
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• pp.677-683
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• 2012

1-octanethiol and vinyl acetate telomers ($R_8S$-nVAc) were synthesized and hydrolyzed with sodium hydroxide subsequently, 1.2-epoxyhexane was then introduced to the telomers. In addition, we prepared cotelomers of multi-alkylated nonionic surfactants with a molecular structure of xRnMA-yVA (x; hydrophobic group, y; hydrophilic group, MA; methacrylic ester, VA; vinyl alcohol, R; and alkyl group) and cross-linked with sodium tetraborate decahydrate. Their active surface properties were investigated by several techniques such as surface tension, foaming property, and emulsification power measurements. The surface tension of $R_8S$-8.8VA decreased without the introduction of 1.2-Epoxy hexane, and the degree of emulsification and foaming abilities of $R_8S$-8.8VA increased without the introduction of 1.2-Epoxy hexane. However, the differences were insignificant. The epoxy groups were attached to a $R_8S$-8.8VA cotelomer with a limited variation of the active surface properties. The surface tension of $1.1R_6MA$-8.8VA decreased after cross-linking subsequently, the degree of emulsification and foaming abilities of $1.1R_6MA$-8.8VA increased after cross-linking. However, there was no clear difference between them. The B-O bonds were attached to a $1.1R_6MA$-8.8VA cotelomer with a limited variation of the active surface properties.

• Journal of the Korean Orthopaedic Association
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• v.56 no.6
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• pp.491-497
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• 2021

Purpose: To investigate the prevalence of osteoporosis or osteopenia via dual-energy X-ray absorptiometry bone mineral density (DEXA BMD) in adult males who showed radiolucent lumbar vertebra on the plain radiographs. Materials and Methods: The DEXA BMD values of 98 adult males, who showed radiolucent vertebrae on plain X-rays, were compared with those of the control group (n=168) and osteoporosis-related fracture group (n=113) by statistical analysis. The World Health Organization (WHO) method (lower value between the mean lumbar and femur neck) and the Hansen's method (lowest lumbar vertebra) were used to determine osteoporosis. Results: The mean and standard deviation of the BMD value of each group was -1.4 (±1.2) in the suspicious group, -0.8 (±1.1) in the control group, and -2.4 (±1.0) in the fracture group, respectively; the difference was statistically significant. Using the WHO method, the prevalence ratio of osteoporosis was 17.3% in the suspicious group, 8.3% in the control group, and 45.1% in the fracture group, respectively. Osteopenia was observed in 40.8% of the suspicious group. Hansen's method (lowest lumbar vertebra) revealed the prevalence of osteoporosis in 30.6% of the suspicious group, 17.9% of the control group, and 62.0% of the fracture group. Conclusion: Approximately 17.3% of the suspicious group was diagnosed with osteoporosis, and 40.8% were osteopenic by a confirmative BMD study (WHO criteria) among the adult males showing apparent radiolucency on plain X-rays. The control group also showed an 8% prevalence of osteoporosis. These results suggest that males also are vulnerable to osteoporosis. Therefore, a BMD study should also be used for males, especially for the people showing lumbar vertebrae with radiolucent features.

• Bulletin of the Korean Mathematical Society
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• v.34 no.3
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• pp.385-394
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• 1997

In this paper, we prove in p-uniforlmy convex space a fixed point theorem for a class of mappings T satsfying: for each x, y in the domain and for n = 1, 2, 3, $\cdots$, $$ \left\$\mid$ T^n x - T^n y \right\$\mid$ \leq a \cdot \left\$\mid$ x - y \right\$\mid$ + b(\left\$\mid$ x - T^n x \right\$\mid$ + \left\$\mid$ y - T^n y \right\$\mid$) + c(\left\$\mid$ c - T^n y \right\$\mid$ + \left\$\mid$ y - T^n x \right\$\mid$, $$ where a, b, c are nonnegative constants satisfying certain conditions. Further we establish some fixed point theorems for these mappings in a Hilbert space, in $L^p$ spaces, in Hardy spaces $H^p$ and in Sobolev spaces $H^{p,k}$ for 1 < p < $\infty$ and k $\leq$ 0. As a consequence of our main result, we also the results of Goebel and Kirk [7], Lim [8], Lifshitz [12], Xu [20] and others.

• Journal of the Korean Institute of Gas
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• v.15 no.6
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• pp.14-19
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• 2011

The objective of this study was to investigate the effect of the thickness eccentricity on the collapse pressure of a subsea pipeline subjected to external pressure. The collapse behavior of the subsea pipeline containing initial imperfection was evaluated using elastic-plastic finite element (FE) analyses. API 5L X65 and API 5L X80 Pipelines with the thickness eccentricity values between 4~16% were adopted to investigate the plastic collapse under hydrostatic pressure. A parametric study was shown that the plastic collapse pressure decreased when either the thickness eccentricity or the ratio of diameter to thickness increased.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.51.1-51.1
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• 2010

이번 연구에서는 저온 용액공정을 이용하여p-type 반도체로 많이 사용되고 있는 $Cu_xS$를 기판 위에 증착하여 그 특성을 분석하였다. $Cu_xS$는 x의 값에 따라 다섯가지의 결정구조를 가지는데 CuS, $Cu_{1.75}S$, $Cu_{1.8}S$, $Cu_{1.95}S$, $Cu_2S$ 들이 그것이다. 태양전지에서 p형 반도체로 중요한 역할을 담당하고 있는 $Cu_xS$는 cell에서 사용되었을 때 energy bandgap이 1.2-2.5eV일 때 가장 좋은 특성을 나타낸다. 이번 연구에서는 특히 조성에 따라서 물리적, 광학적으로 어떤 특성을 나타내는지에 대하여 XRD, SEM, Uv-vis 등의 분석을 해보았다. XRD의 경우 농도가 높아질수록 peak의 intensity는 커지지만 어느 농도 이상부터는 Cu가 Oxide화 되는 것을 관찰할 수 있었다. SEM image의 경우에는 조성에 따른 포면의 상태를 분석해보았다. 조성에 따른energy bandgap을 알아보기 위해서는 Uv-vis을 측정하였으며 이를 이용하여 증착된 박막의 투과도 역시 함께 분석해보았다.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.355-359
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• 2010

A $Li[Co_{1/3}Ni_{1/3}Mn_{1/3}]O_2$ cathode was modified by applying a $ZrF_x$ coating. The surface-modified cathodes were characterized by XRD, SEM, EDS, TEM techniques. XRD patterns of $ZrF_x$-coated $Li[Co_{1/3}Ni_{1/3}Mn_{1/3}]O_2$ revealed that the coating did not affect the crystal structure of the parent powder. SEM and TEM images showed that $ZrF_x$ nano-particles were formed as a coating layer, and EDS data confirmed that $ZrF_x$ distributed uniformly on the surface the powder. Capacity retention of coated samples at high C rates was superior to that of pristine sample. However, as the coating concentration increases beyond the optimum concentration, the rate capability was deteriorated. Whereas, as the increase of coating concentration to 2.0 wt %, the cyclic performances of the electrodes under the severe conditions (high cut-off voltage, 4.8 V, and high measurement temperature, $55^{\circ}C$) were improved considerably.