• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.225-225
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• 2011

The dielectric and optical properties of GaInZnO (GIZO), HfInZnO (HIZO) and InZnO (IZO) thin films on glass by RF magnetron sputtering method were investiged using reflection electron energy loss spectroscopy (REELS). The band gap was estimated from the onset values of REELS spectra. The band gaps of GIZO, HIZO and IZO thin films are 3.1 eV, 3.5 eV and 3.0 eV, respectively, Hf and Ga incorporated into IZO results in an increase in the energy band gap of IZO by 0.5 eV and 0.1 eV. The dielectric functions were determined by comparing the effective cross section determined from experimental REELS with a rigorous model calculation based on the dielectric response theory, using available software package, good agreement between the experimental and fitting results gives confidence in the accuracy of the determined dielectric function. The main peak of Energy Loss Function (ELF) obtained from IZO shows at 18.42 eV, which shifted to 19.43 eV and 18.15 eV for GIZO and HIZO respectively, because indicates the corporation of cation Ga and Hf in the composition. The optical properties represented by the dielectric function e, the refractive index n, the extinction coefficient k, and the transmission coefficient, T of HIZO and IZO thin films were determined from a quantitative analysis of REELS. The transmission coefficient was increased to 93% and decreased to 87% in the visible region with the incorporation of Hf and Ga in the IZO compound.

• Journal of the Mineralogical Society of Korea
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• v.26 no.4
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• pp.285-297
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• 2013

Ilmenite deposits are developed along the Precambrian intercumulated anorthosite body in Jikjeon-Ri, Bukcheon-Myeon, Hadong, Korea. Both detailed geological survey and drilling prospecting data for seven boreholes can be used to do resource estimation with GOCAD S/W. 3D modeling using geostatistics is applied to predict the shape and size of Ti ore bodies. As a result, 5 Ti ore veins occurred along N-S direction and average grade of Ti and ilmenite resources are calculated as 2.98 wt% Ti and 7,494,303 metric tons ilmenite ore reserves (Ti 223,330 t). This 3D modeling will be applied to the whole ilmenite deposits in Hadong-Sancheong area to predict the exact distribution and resources estimations of Ti ores.

• Korean Journal of Materials Research
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• v.6 no.7
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• pp.692-699
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• 1996

nptype Si(100)웨이퍼를 precleaning하고 HF 용액에 dip etching한 후 E-beam dvaporator에 장착하여 Co 단일막($170\AA$, $340\AA$)과 Co/Ti 이중막($200\AA$/ $(50-100)\AA$)을 성장시켰다. 시편의 RTA 과정에서는 N2분위기에서 direct annealing 방식으로 열처리 온도와 시간을 변화시켜가며 Co-silicidation 공정을 수행하였다. Co 단일막으로 형성된 Co-실리사이드의 면저항은 $500^{\circ}C\leq$T$\leq$$850^{\circ}C$범위에서 열처리 온도와 시간의 변화에 관계없이 거의 일정한 값을 나타내었다. Co/Ti 이중막의 경우 Co-실리사이드의 형성온도가 Co 단일막의 경우에 비해 높게 나타나고 낮은 비저항의 CoSi2를 얻기 위해서는 $800^{\circ}C$이상의 온도로 열처리해야 함을 알 수 있었다. XRD 분석결과, Co 단일막으로부터 얻어진 CoSi2는 (111) 및 (220) 결정상을 나타내었으나, Co/Ti 이중막에 의한 CoSi2는 (200)결정상만이 나타나서 Si(100)기판과 에피층을 이루고 있음을 알 수 있었다. 본 실험에서 CoSi2의 비저항은 약 $18\mu$$\Omega$.cm로 나타났으며, TEM 및 AES 분석으로부터 Co/Ti bilayer-실리사이드가 다량의 Si과 Ti 외에 소량의 Co가 섞여있는 표면 복합층과, Si과 Co만이 존재하는 내부 에피층으로 구성됨을 확인하였다.

• Journal of Biosystems Engineering
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• v.30 no.6 s.113
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• pp.366-372
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• 2005

The objective of this study was to evaluate the bump crossing and loading stability of a proto-type mini-forwarder under development. The evaluation was performed by computer simulation using a multi-body dynamic analysis program, Recur- Dyn 5.21. The proto-type was modeled and its properties such as mass, mass center, and mass moment of inertia were determined using 3D CAD modeler, Solid Edge 8.0. The $\%$ errors of masses, mass center, mass moment of inertia, and vertical motion of the model were within less than $10\%$ and the model's behavior agreed relatively well with those of the proto-type when traversing over a rectangular bump. Using the validated model, bump crossing of the proto-type was simulated and the loading limit was determined. It was found that effects of the shapes of bump on the bump crossing performance was insignificant within the practical heights of bumps. Stability of bump crossing increased with loading. However, loading of longer logs than 2.7 m made the crossing unstable because the ends of logs contacted ground when traversing over the bump. The maximum loading capacity of the proto-type was estimated to be 7.8 kN of 2.7 m long logs.

• The Korean Journal of Pain
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• v.12 no.1
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• pp.81-86
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• 1999

Background: Essential hyperhidrosis is a condition with excessive sweating, which may be localized in any parts of the body. Thoracic sympathectomy has been a surgical procedure for the management of hyperhidrosis. Methods: We studied 30 ASA I and II patients suffering from severe hyperhidrosis. Bilateral upper thoracoscopic sympathectomy of $T_{2-4}$ was performed in 30 patients under general anesthesia. Anesthesia was induced with 2.5% thiopental sodium 5 mg/kg and succinylcholine chloride 1 mg/kg and was maintained with enflurane 1~2 Vol% and $N_2O-O_2$ mixture adjusted to maintain $SpO_2$ greater than 96%. During anesthesia, invasive arterial pressure, heart rate, EKG, $SpO_2$ and capnography were monitored. Skin temperature was measured with thermister probes attached to the index finger of each hand. An increase in temperature after cautery confirmed success of the sympathectomy. Results: There were 14 men and 16 women whose ages ranged from 16 to 46 years old (mean age 22.2). Of these patients, 13 patients had complained of palm-sole hyperhidrosis, 9 of palm-sole-axilla hyperhidrosis, 4 of palm-sole-face hyperhidrosis and 4 of palm-sole-axilla-face hyperhidrosis. The provocative factors of excessive sweating were tension and stress from interpersonal relationships. There was positive familial history in 37%. The most common complication was compensatory hyperhidrosis in 23 patients comprising 76%. Other complication included peumothorax (4 patients), hemothorax (1 patient), ipsilateral Horner's syndrome (1 patient) and paresthesia of right arm (1 patient). The degree of satisfaction was graded as good, fair and poor with 15, 12 and 3 patients, respectively. Conclusions: Thoracoscopic sympathectomy with VATS is an efficient, safe and minimally invasive surgical procedure for essential hyperhidrosis.

• Journal of Pharmaceutical Investigation
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• v.30 no.1
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• pp.21-26
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• 2000

Bioavailability of ipriflavone (3-phenyl-7-isopropoxy-4H-I-benzopyran-4-one, IP), an antiosteoporotic drug with poor water-solubility, was studied for various types of pharmaceutical preparation in SD rats. The IP preparation types included (1) intact IP, (2) freezer milled IP (FIP), (3) freezer milled IP physically mixed with freezer milled poly-N-vinylpyrrolidone (PVP) (FIP+FPVP) and (4) spray-dried IP with PVP (SIP). Upon oral administration, SIP showed significantly higher absorption and elimination half-lives and the lag time $(t_{lag})$ than those of FIP+FPVP (approximately 2-fold). These results may be due to a sustained releasing effect of IP in the gastrointestinal tract by spray-drying with PVP. The $C_{max}$ of SIP was about 2 and 10 times higher than those of FIP+FPVP and FIP, respectively. The AUC of SIP was about 6 times higher than that of FIP+FPVP and 60 times that of FIP. Scanning electron microscopy (SEM) showed that SIP consisted of the finest particle size and minimal aggregation than other IP preparations. It is concluded that the IP formula prepared by the spray-drying method with PVP is the most effective approach to the improvement of bioavailability of IP.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.4
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• pp.224-230
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• 2000

Garbon steel(SM35C) was gas nitrocarburized at $580^{\circ}C$ in $55%N_2-40%NH_3-5%CO_2$ mixed gas atmosphere, and then the steel was induction hardened at $850^{\circ}C$. The microstructure of gas nitrocarburized surface layer was observed by optical microscope and SEM. The phase analysis was carried out by X-ray diffraction method. The mechanical properties of gas nitrocarburized SM35C steel was evaluated by hardness, wear and fatigue test. The thickness of compound and diffusion layer were increased with increasing the gas nitrocarburizing time and the densest compound layer was obtained at 3 hours gas nitrocarburizing time. In case of 15sec induction hardening after gas nitrocarburizing, the surface hardness was decreased from 800Hv to 630Hv owing to the decomposition of compound layer, but wear resistance was increased because of increased hardness of diffusion layer. The fatigue strength of induction hardened steel after gas nitrocarburizing, $58kgf/mm^2$, was higher than $41.5kg/mm^2$ of gas nitrocarburized steel and $45kg/mm^2$ of induction hardened steel, respectively.

• Journal of the Korean Society for Heat Treatment
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• v.14 no.4
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• pp.220-227
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• 2001

The static creep behaviors of dispersion strengthened copper GlidCop were investigated over the temperature range of $650{\sim}690^{\circ}C$ (0.7Tm) and the stress range of 40~55 MPa (4.077~5.61 $kg/mm^2$). The stress exponents for the static creep deformation of this alloy was 8.42, 9.01, 9.25, 9.66 at the temperature of 690, 677, 663, and $650^{\circ}C$, respectively. The stress exponent, (n) increased with decreasing the temperature and became dose to 10. The apparent activation energy for the static creep deformation, (Q) was 374.79, 368.06, 361.83, and 357.61 kg/mole for the stress of 40, 45, 50, and 55 MPa, respectively. The activation energy (Q) decreased with increasing the stress and was higher than that of self diffusion of Cu in the dispersion strengthened copper. In results, it can be concluded that the static creep deformation for dispersion strengthened copper was controlled by the dislocation climb over the ranges of the experimental conditions. Larson-Miller parameter (P) for the crept specimens for dispersion strengthened copper under the static creep conditions was obtained as P=(T+460)(logtr+23). The failure plane observed for SEM slightly showed up transgranular at that experimental range, however, universally it was dominated by characteristic of the intergranular fracture.

• Restorative Dentistry and Endodontics
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• v.41 no.1
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• pp.1-5
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• 2016

Objectives: The purpose of this study was to assess the ability of ProTaper Gold (PTG, Dentsply Maillefer) in maintaining the original profile of root canal anatomy. For that, ProTaper Universal (PTU, Dentsply Maillefer) was used as reference techniques for comparison. Materials and Methods: Twenty simulated curved canals manufactured in clear resin blocks were randomly assigned to 2 groups (n = 10) according to the system used for canal instrumentation: PTU and PTG groups, upto F2 files (25/0.08). Color stereomicroscopic images from each block were taken exactly at the same position before and after instrumentation. All image processing and data analysis were performed with an open source program (FIJI). Evaluation of canal transportation was obtained for two independent canal regions: straight and curved levels. Student's t test was used with a cut-off for significance set at ${\alpha}=5%$. Results: Instrumentation systems significantly influenced canal transportation (p < 0.0001). A significant interaction between instrumentation system and root canal level (p < 0.0001) was found. PTU and PTG systems produced similar canal transportation at the straight part, while PTG system resulted in lower canal transportation than PTU system at the curved part. Canal transportation was higher at the curved canal portion (p < 0.0001). Conclusions: PTG system produced overall less canal transportation in the curved portion when compared to PTU system.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.181-186
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• 2010

Characteristics of household wastes production from fishing village in small island was investigated. Investigation was conducted in August and December to represent seasonal characteristics of summer and winter, respectively. Amount of household wastes production was 0.65 kg/capita·day and this is relatively low value compared with nationwide average. Food wastes, papers, vinyl and plastics are major part of combustible portion in household wastes. Composting is inappropriate method as a final disposal method in terms of C/N ratio calculated from elemental analysis. It is recommended that incineration can be appropriate way as a final disposal method of household wastes because low heating value of household wastes is equivalent to that of crude oil. The fraction of food wastes in household is considerably higher than the values obtained from other residential areas in nationwide. Thus, it is evaluated that household composting devices and vermicomposting facilities are necessary to reduce the amount of food wastes. It also can be evaluated that incineration is optimal method as disposal method of household wastes from fishing village except food wastes.