• Bulletin of the Korean Chemical Society
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• v.26 no.7
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• pp.1065-1070
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• 2005

$[Mn_{12}O_{12}(O_2CPh-4-SMe)_{16}(H_2O)_4]{\cdot}7CH_2Cl_2$ (1), a new single-molecule magnet complex has been successfully synthesized by substitution of acetate ligand of Mn12ac with 4-(methylthio)benzoic acid. Complex 1 crystallizes into triclinic P$\overline{1}$ with a = 18.321(3) $\AA$, b = 19.011(3) $\AA$, c = 27.230(4) $\AA$, $\alpha$ = 86.973(3)$^{\circ}$, $\beta$ = 76.919(3)$^{\circ}$, $\gamma$ = 87.613(3)$^{\circ}$, and Z = 2. In complex 1, one Mn(III) ion has an abnormal Jahn-Teller elongation axis oriented at an oxide ion. Complex 1 has two out-of-phase ac susceptibility peaks in the 2-4 K and 4-7 K regions. Effective anisotropy energy barrier and pre-exponential factor are $U_{eff}$ = 45.95 K, 1/$\tau$0 = 8.6 ${\times}\;10^9s^{-1}\;for\;{\chi}_M$'' peaks in the lower temperature region and $U_{eff}$ = 59.45 K, 1/$\tau_0$ = 2.2 ${\times}\;10^8\;s^{-1}$ for $\chi_M$'' peaks in the higher temperature region. The parameters of S = 10, g = 1.87, D = -0.40 $cm^{-1}$, and E = 0.00034 $cm^{-1}$ were obtained from the M/N${\mu}_B$ vs. H/T plot of complex 1.

• Korean Journal of Materials Research
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• v.4 no.4
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• pp.406-415
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• 1994

The effects of fabrication method and condition on critical current density of Ag sheathed Bi- 2223 superconducting tapes by powder-in-tube method were studied. The highest critical current density (Jc) in the whole process was measured in the repeative heat treatment of 250 hour and mechanical deformation of 2 times. These results are suggested that the high-Tc phase at the heat treatment of 250 hour was superior and the good grain alignment at the mechanical deformation of 2 times was analyzed by XRD pattern. The highest critical current density obtained by pressing method was $1.05\times 10^4A/\textrm{cm}^2$ and $0.78\times 10^4A/\textrm{cm}^2$ in case of rolling method. The multifilamentary wires with 7 and 49 filaments were fabricated to check the applicability of pressing and rolling method for preparing multifilaments wire. The critical current density of 7 filaments tapes prepared by pressing showed $0.45 \times 10^{4}A/\textrm{cm}^2$ and $0.20 \times 10^{4}A/\textrm{cm}^2$ for 49 filaments tapes prepared by rolling.

• The Korean Journal of Food And Nutrition
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• v.15 no.3
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• pp.209-214
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• 2002

This study was carried out to investigate the physicochemical properties of aloe added bagel. The result of sensory evaluation showed that addition of the aloe powder above 1% was not advisable because of its bitterness. freeze dried aloe powder(0, 1%, 0.5%, 1%) was added to bagel and chemical compositions of doughs were evaluated. The ash content of control was 0.444% and each of the samples(0.1%, 0.5%, 1%) was 0.472%, 0.553%, and 0.633% respectively. Although the ash content of dough increased gradually according to the addition of aloe powder, the volume of the bagel was not affected much. As the amount of the aloe powder was changed, the water absorption rate, the extensibility, and the viscosity of the dough were affected. The physical characteristics of dough were as follows: 1) The water absorption rate of the dough was gradually decreased from 65.3% at control, to 65.2% at 0.1%, 64.2% at 0.5%, 63.5% at 1% each by farinograph. 2) The extensibility of the dough was significantly declined at 1% by extensograph; from 20.7cm at control, to 20.3cm at 0.1%, 18.8cm at 0.5%, and 16.4cm at 1% each. 3) The top viscosity of the dough was sharply declined between 575 B.U at control and 515 B.U at 0.1%, afterwards, 480 B.U at 0.5%, 475 B.U at 1% each by viscograph. Considering the result of the test, aloe added bagel could promote physicochemical properties of dough as well as health effects.

• Earthquakes and Structures
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• v.7 no.4
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• pp.511-525
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• 2014

The main object of this study is to determine and compare the structural behavior of base isolated long span highway bridge, $G\ddot{u}lburnu$ Highway Bridge, using single concave friction pendulum (SCFP) and triple concave friction pendulum (TCFP). The bridge is seismically isolated in the design phase to increase the main period and reduce the horizontal forces with moments using SCFP bearings. In the content of the paper, firstly three dimensional finite element model (FEM) of the bridge is constituted using project drawings by SAP2000 software. The dynamic characteristics such as natural frequencies and periods, and the structural response such as displacements, axial forces, shear forces and torsional moments are attained from the modal and dynamic analyses. After, FEM of the bridge is updated using TCFP and the analyses are performed. At the end of the study, the dynamic characteristics and internal forces are compared with each other to extract the TCFP effect. To emphasize the base isolation effect, the non-isolated structural analysis results are added to graphics. The predominant frequencies of bridge non-isolated, isolated with SCFP and isolated with TCFP conditions decreased from 0.849Hz to 0.497Hz and 0.338Hz, respectively. The maximum vertical displacements are obtained as 57cm, 54cm and 44cm for non-isolated, isolated with SCFP and isolated with TCFP conditions, respectively. The maximum vertical displacement reduction between isolated with TCFP bearing and isolated with SCFP bearing bridge is %23. Maximum axial forces are obtained as 60619kN, 18728kN and 7382kN, maximum shear forces are obtained as 23408kN, 17913kN and 16249kN and maximum torsional moments are obtained as 24020kNm, 7619kNm and 3840kNm for non-isolated, isolated with SCFP and isolated with TCFP conditions, respectively.

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2410-2414
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• 2020

Heavy ions have a high potential for destroying deep tumors that carry the highest dose at the peak of Bragg. The peak caused by a single-energy carbon beam is too narrow, which requires special measures for improvement. Here, carbon-12 (¹²C) ion with different energies has been used as a source for calculating the dose distribution in the water phantom, soft tissue and bone by the code of Monte Carlobased FLUKA code. By increasing the energy of the initial beam, the amount of absorbed dose at Bragg peak in all three targets decreased, but the trend for this reduction was less severe in bone. While the maximum absorbed dose per bone-mass unit in energy of 200 MeV/u was about 30% less than the maximum absorbed dose per unit mass of water or soft tissue, it was merely 2.4% less than soft tissue in 400 MeV/u. The simulation result showed a good agreement with experimental data at GSI Darmstadt facility of biophysics group by 0.15 cm average accuracy in Bragg peak positioning. From 200 to 400 MeV/u incident energy, the Bragg peak location increased about 18 cm in soft tissue. Correspondingly, the bone and soft tissue revealed a reduction dose ratio by 2.9 and 1.9. Induced neutrons did not contribute more than 1.8% to the total energy deposited in the water phantom. Also during ¹²C ion bombardment, secondary fragments showed 76% and 24% of primary 200 and 400 MeV/u, respectively, were present at the Bragg-peak position. The combined treatment of carbon ions with neutron or electron beams may be more effective in local dose delivery and also treating malignant tumors.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2410-2412
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• 2005

In this study, two types of PS substrate were fabricated for sensing of chemical and biological substances. For sensing of the humidity and chemical analyzes such as $CH_3OH$ or $C_2H_5OH$, PS layers are prepared by photoelectrochemical etching of silicon wafer in aqueous hydrofluoric acid solution. To evaluate their sensitivity, we measured the resistance variation of the PS diaphragm. As the amplitude of applied voltage increases from 2 to 6Vpp at constant frequency of 5kHz, the resistance variation for humidity sensor rises from 376.3 to $784.8{\Omega}$/%RH. And the sensitivities for $CH_3OH$ and $C_2H_5OH$ were 0.068 uA/% and 0.212 uA/%, respectively. For biological sensing application, amperometric urea sensors were fabricated based on porous silicon(PS), and planar silicon(PLS) electrode substrates by the electrochemical methods. Pt thin film was sputtered on these substrates which were previously formed by electrochemical anodization. Poly (3-methylthiophene) (P3MT) were used for electron transfer matrix between urease(Urs) and the electrode phase, and Urs also was by electrochemically immobilized. Effective working area of these electrodes was determined for the first time by using $Fe(CN)_6^{3-}/Fe(CN)_6^{4-}$ redox couple in which nearly reversible cyclic voltammograms were obtained. The $i_p$ vs $v^{1/2}$ plots show that effective working electrode area of the PS-based Pt thin film electrode was 1.6 times larger than the PLS-based one and we can readily expect the enlarged surface area of PS electrode would result in increased sensitivity by ca. 1.6 times. Actually, amperometric sensitivity of the Urs/P3MT/Pt/PS electrode was ca 0.91uA/$mM{\cdot}cm^2$, and that of the Urs/P3MT/Pt/PLS electrode was ca. 0.91uA/$mM{\cdot}cm^2$ in a linear range of 1mmol/L to 100mmol/L urea concentrations

• Korean Journal of Head & Neck Oncology
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• v.15 no.1
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• pp.66-69
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• 1999

Background and Objectives: It is critical to distinguish benign from malignant thyroid nodule and to select a patient for surgery. Even though the U/S study dose not make great contribution to diagnose a malignant thyroid nodule, it is widely used in the evaluation of anatomic feature of thyroid. The authors tried to estimate the efficacy of the U/S study in preoperative diagnosis of malignant thyroid nodule. Materials and Method: At the department of General Surgery of Ajou University, 75 patients who were operated after diagnosis with thyroid nodule by U/S study between July 1996 to June 1997 were retrospectively analyzed. By comparing the U/S impression that implies malignant thyroid nodule to FNAC and post-operative pathologic results ware as follows. Results: 1) Absence of cystic change, presence of internal hypoechogenicity, lobulation, calcification, thick and irregular halo, and nodule more than 4cm in diameter on U/S were considered significant statistically for the diagnosis of malignancy(Chi-square test, p<0.05) 2) Presence of internal hypoechogenicity or thick and irregular halo has the validity in Logistic regression analysis. 3) FNAC was done in 65 case. 19 case were malignant, 11 case were suspicious and 46 patients were benign (sensitivity 52.6%, specificity 87%). 4) The findings of U/S which are hypoechogenic and thick and irregular halo show 82% sensitivity and 97% specificity. In combination with the findings of FNAC that imply benign or suspicious lesions, the sensitivity was 100% and the specificity was 97%. Conclusion: This study suggest that the hypoechogenicity and thick and irregular halo on U/S are important information for the diagnosis of thyroid malignancy which were considered benign or suspicious after FNAC.

• Korean Journal of Head & Neck Oncology
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• v.13 no.2
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• pp.206-212
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• 1997

H$\"{u}$rthle cell neoplasm of the thyroid gland is an uncommon, but potentially malignant lesion. However, in many instances, the malignant potential of the H$\"{u}$rthle cell neoplasm is very difficult to judge histologically. For this reason, the biologic behavior of this tumor and its optimal treatment have come under considerable debate in recent years. In order to review the clinicopathologic features of the H$\"{u}$rthle cell neoplasm and to determine its optimal treatment modalities, we studied 26 patients with path logical proof of H$\"{u}$rthle cell tumor from January 1987 to September 1997. We also performed an immunohistochemical study using the monoclonal antibodies against antigen CD34 for the angiogenic activity of this tumor and evaluated the differences of microvessel density(MVD) between benign and malignant tumors. The age of the patients ranged from 1 to 71 years with a mean of 44.2 years. There were 6 males and 20 females(M : F= 1 : 3.3). The accuracies of fine needle aspiration biopsy and frozen section were very low; 6.3% and 34.8%, respectively. There were 20 benign tumors and 6 malignant tumors(23.1%). All the malignant tumors were microinvasive(intermediate) type which had minimal capsular invasion and most of them(5 cases) were diagnosed postoperatively. Any specific clinicopathologic differences were not seen between benign and intermediate groups. Most of the cases had conservative surgeries(15 ipsilateral lobectomy-isthmusectomy, 7 subtotal thyroidectomy) while total thyroidectomy was performed in 4 cases. Of the cases with malignant tumor, 2 had ipsilateral lobectomy-isthmusectomy, 3 had subtotal thyroidectomy and the remaining 1 had total thyroidectomy. Mean size of the tumors was 3.0 cm(0.1- 8.5 cm) in the greatest diameter and multiple tumors were seen in 6 cases(23.1 %). During the follow-up period, only one recurrence(3.8%) of benign tumor occurred but distant metastasis or cause-specific death was seen in the benign or intermediate groups. Mean MVDs of the benign(n=13) and intermediate(n=6) groups were $121.7{\pm}35.3$ and $114.3{\pm}31.7$, respectively and there was no statistical significance between them. In conclusion, because of the low accuracies of fine needle aspiration biopsy and frozen section for the H$\"{u}$rthle cell neoplasm, the extent of surgery could be individualized based on permanent pathologic examination; Conservative surgery would be adequate for patients with benign or intermediate H$\"{u}$rthle cell neoplasm and total or near-total thyroidectomy for those with definite malignancy.

• Journal of Nutrition and Health
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• v.4 no.1
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• pp.29-40
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• 1971

For the measurement on the fat content if University Students, an intensive examination was conducted on a total of 3,030 students(male 2,577, female 453), from 16 to 25 years of age. The subjects were all students who had passed the written entrance examination for Seoul National University. Total Body Fat amount was measurement by skin-fold thickness with a skin-fold caliper(Manufactured by Cambridge Scientific Industrial Inc. U.S.A.) at four sites of the body, and it was calculated by Kim's and Lee's regression equation. As a result of this survey, the following conclusions were obtained; 1. Physical Measurements: i) The average of body height by anthropometric was male $167.95{\pm}4.85cm$ and female $156.03{\pm}4.56cm$. ii) The average body weight by anthropometric was male $56.42{\pm}5.65kg$ and female $51.29{\pm}5.34kg$. iii) The average of chest-girth by anthropometric was male $89.95{\pm}5.33cm$ and female $81.36{\pm}4.89cm$. iv) The average of sitting-height by anthropometric was male $91.23{\pm}4.98cm$ and female $86.18{\pm}4.15cm$. v) The average of arm circumference by anthropometric was male $23.76{\pm}2.17cm$ and female $22.39{\pm}1.79cm$. In all cases the male measurements were higher than the female. 2. The mean skin-fold thickness measured with a large skin-fold caliper was; At the sub-scapular: male $11.54{\pm}4.84mm$ and female $14.07{\pm}4.49mm$, Abdominal: male $10.36{\pm}7.09mm$ and female $14.95{\pm}5.47mm$, Lumbar; male $12.55{\pm}6.44mm$ and female $17.02{\pm}6.57mm$, Upper arm: male $6.28{\pm}3.71mm$ and female $11.62{\pm}3.99mm$, Total average: male $10.18{\pm}5.52mm$ and female $14.41{\pm}5.13mm$, in all cases the female measurements were higher than the male. 3. Data on body fat amounts according to body fat weight regression equation were: in male: Fat weight=10.56kg, Fat free weight=45.86kg, Fat weight/Total body mass(%)=18.71%, (Body fat amount %), Fat weight/Fat free weight(%)=23.02%, Fat free weight/Total body mass(%)=81.29%. in female: Fat weight=12.23kg, Fat free weight=39.06kg, Fat weight/Total body mass(%)=23.85%, Fat weight/Fat free weight(%)=31.31%, Fat free weight/Total body mass(%)=76.15%. The females value was higher than the males.

• Journal of Chest Surgery
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• v.19 no.4
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• pp.699-706
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• 1986

We have experienced 5 cases of Pectus excavatum corrected by Ravitch method without use of K-wire or metal bar from Jan. 1985 to Apr. 1986. All cases were male. The symmetric depression was in 4 cases, asymmetric one was in one case. The chief complaints were dyspnea on exertion, frequent U.R.I. and inferiority. The flail chest was developed in all cases, but it was insignificant in all cases except one who needed assist ventilation. Mediastinitis was developed in one case one week postoperatively but well managed with drainage. A distance from the posterior surface of sternum to the anterior surface of vertebral body was estimated preoperatively and postoperatively. Postoperative result was evaluated as the change of distance postoperatively. The change was 1.5cm minimally to 3.5cm maximally. Late results were "Excellent" in 3 cases and "Good" in 2 cases.uot; in 2 cases.