• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.3088-3095
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• 2000

Creep-fatigue crack growth behavior was experimentally measured particularly when a crack was located in the heat affected region of lCr-5Mo steel. Load hold times of the tests for trapezoidal fatigue waveshapes were varied among 0, 30, 300 and 3,600 seconds. Time-dependent crack growth rates were characterized by the $C_r$parameter. It was found that the crack growth rates were the highest when the crack path was located along the fine-grained heat affected zone(FGHAZ). Cracks located in other heat affected regions had a tendency to change the crack path eventually to FGHAZ. Creep-fatigue crack growth law of the studied case is suggested in terms of (da/dt)$_{avg}$ vs. ($C_t$)$_{avg}$ for residual life assessment.

• Archives of Pharmacal Research
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• v.12 no.3
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• pp.186-190
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• 1989

The release rates of methotrexate (MTX) from MTX-human serum albumin (HSA) conjugate, and 5-fluorouracil (5-FU) from 5-FU acetic acid (AA)-HSA conjugate were determined after incubation of the conjugates in various conditions. The concentrations of 5-FU released from the conjugate increased monoexponentially, however those of MTX increased biexponentially in all studies. It indicated that there are two distinct types of MTX-HSA linkage, weakly and tightly bound linkages. The release rates of 5-FU were lower than those of MTX in all studies indicating that the bond of 5-FU-AA-HSA conjugate is very stable, which is supported by the higher value of activation energy (39. 9 vs 10. 7 Kcal/mole) using Arrhenius equation. The release rates of MTX and 5 -FU from the conjugates increased with incubation temperatures. Proteolytic enzyme and liver homogenates accelerated significantly the release rates of MTX and 5-FU. Approximately 1.30 and 22.0% of MTX were released after 12 hours of incubation in the absence and presence of protease, respectively. The corresponding values for 5-FU were released after 12 hours of incubation with rat liver homogenates which were diluted 6 times with phosphate buffer of pH 6.0. The MTX-HSA and 5-FU-AA-HSA conjugates were very stable in rat plasma.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.29-29
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• 1999

The synthesis of layered structures on the nanometer scale has become essential for continued improvements in the operation of various electronic and magnetic devices. Abrupt metal-metal interfaces are desired for applications ranging from metallization in semiconductor devices to fabrication of magnetoresistive tunnel junctions for read heads on magnetic disk drives. In particular, characterizing the interface structure between various transition metals (TM) and aluminum is desirable. We have used the techniques of MeV ion backscattering and channeling (HEIS), x-ray photoemission (ZPS), x-ray photoelectron diffraction(XPD), low-energy ion scattering (LEIS), and low-energy electron diffraction(LEED), together with computer simulations using embedded atom potentials, to study solid-solid interface structure for thin films of Ni, Fe, Co, Pd, Ti, and Ag on Al(001), Al(110) and Al(111) surfaces. Considerations of lattice matching, surface energies, or compound formation energies alone do not adequately predict our result, We find that those metals with metallic radii smaller than Al(e.g. Ni, Fe, Co, Pd) tend to form alloys at the TM-Al interface, while those atoms with larger atomic radii(e.g. Ti, Ag) form epitaxial overlayers. Thus we are led to consider models in which the strain energy associated with alloy formation becomes a kinetic barrier to alloying. Furthermore, we observe the formation of metastable fcc Ti up to a critical thickness of 5 monolayers on Al(001) and Al(110). For Ag films we observe arbitrarily thick epitaxial growth exceeding 30 monolayers with some Al alloying at the interface, possible driven by interface strain relief. Typical examples of these interface structures will be discussed.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.201-203
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• 2005

To improvement the performance of PDPs, we developed an ac-PDP with new fence structure. By measuring minimum sustaining voltage(Vs), discharge current(Ion), discharge(Ioff), and brightness of the light from a 4-inch at-PDP, performances of the conventional structure and proposed structure are compared. The experimental results show that the test panel with the proposed new fence structure shows high luminance by 10%, and high luminous efficiency by 30% compared with the conventional structure at the Ne-Xe(8%) gas mixture of 400 torr.

• Advances in biomechanics and applications
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• v.1 no.4
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• pp.269-277
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• 2014

In skin-marker based motion analysis, knee translation measurement is highly dependent on a pre-selected reference point (functional center) on each segment determined by the location of anatomical landmarks. However, the placement of skin markers on palpable anatomical landmarks (i.e., femoral epicondyles) has limited reproducibility. Thus, it produces large variances in knee translation measurement among different subjects, as well as across studies. In order improve the repeatability of knee translation measurement, in this study an optimization method was introduced, by which the femoral functional center was numerically determined. At that point the knee anteroposterior translation during the stance phase of walking was minimized. This new method was tested on 30 healthy subjects during walking in gait lab with motion capture system. Using this new method, the impact of skin marker position (at anatomical landmarks) on the knee translation measurement has been minimized. In addition, the ranges of anteroposterior knee translations during stance phase were significantly (p<0.001) smaller than those measured by conventional method which relies on a pre-selected functional center ($11.1{\pm}3.5mm$ vs. $19.9{\pm}5.5mm$). The results of anteroposterior translation using this new method were very close to a previously reported knee translation (12.4 mm) from dual fluoroscopic imaging technique. Moreover, this new method increased the reproducibility of knee translation measurement by 50%.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5829-5833
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• 2014

Background: The role of processed meat in the aetiology of squamous cell oesophageal cancer has been explored in detail. Methods: In the time period 1990-2005, a case-control study was conducted in Montevideo, Uruguay including 2,368 participants (876 cases of oesophageal cancer and 1,492 controls). Relative risks, approximated by the odds ratios, were estimated by multiple unconditional logistic regression. Results: Processed meat was positively associated with oesophageal cancer (upper quartile vs lower quartile OR 2.30, 95%CI 1.72-3.07), whereas salted meat intake was positively associated with squamous cell oesophageal cancer (OR 3.82, 95%CI 2.74-5.33). Finally other cured meats were positively associated with oesophageal cancer (OR 1.65, 95%CI 1.22-2.22). Conclusions: It could be concluded that processed meat consumption could be an important risk factor for the aetiology of squamous cell oesophageal cancer in Uruguay.

• Korean Journal of Materials Research
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• v.6 no.9
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• pp.885-899
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• 1996

초강인 AISI 4340강을 85$0^{\circ}C$에서 2시간 동안 오스테나이징 처리 후 수냉하고, 250, 400, $600^{\circ}C$에서 각각 2시간 동안 템퍼링 처리를 하였다. AISI 4340강의 인장 특성은 상온에서 측정되었다. AISI 4340강 위에 니켈 전해도금된 것과 도금되지 않은 시편의 분극 특성이 3.5wt%NaCI 수용액과 인공해수에서 측정되었다. AISI 4340강위에 니켈 전해도금된 시편은 500mV(vs. Ag/AgCI)이하의 전위에서 부식 저항이 크게 향상되었다. 그러나 1A/$\textrm{cm}^2$의 전류밀도에서 30분 이상 니켈 전해도금된 시편은 도금층에 불순물과 기공이 형성되었기 때문에 AISI 4340강의 부식 저항은 감소되었다. AISI 4340강의 수소취화형 응력부식균열을 여러 작용 응력과 음극인가전력에서 U-bend 시편을 이용하여 IN 3.5 wt% NaCI 수용액에서 조사되었고, 수소취화형 응력부식균열 거동은 주사전자현미경으로 조사되었다.

• Advances in Traditional Medicine
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• v.9 no.3
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• pp.232-237
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• 2009

The effect of arogh, a polyherbal formulation-PHF [each 3 g powder contained Nelumbo nucifera G. (0.24 g), Hemidesmus indicus R. (0.24 g), Zingiber officinale R. (0.24 g), Terminalia chebula R. (0.24 g), Quercus infectoria O. (0.12 g), Hibiscus rosa-sinensis L. (0.24 g), Rosa damascene M.(0.24 g), Eclipta alba H.(0.24 g), Glycyrrhiza glabra L. (0.24 g)] was investigated in various experimental models of pain and inflammation. Analgesic activity of PHF was studied in mice using acetic acid induced writhing, tail immersion and hot plate methods. Anti-inflammatory activity of PHF was studied in rats using carrageenan induced hind paw edema and formalin induced rat paw edema methods. PHF significantly (P < 0.05) reduced the number of writhings, increased latency to flick tail in tail immersion method and elevated the mean basal reaction time in hot plate method. PHF significantly (P < 0.05) inhibited carrageenan induced hind paw edema and formalin induced rat paw edema. The PHF was tested at dose of 30, 100, 300 and 500 mg/kg.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.178-182
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• 1996

Background: To evaluate the effect of prophylactic transdermal scopolamine in reducing nausea associated with postoperative epidural morphine. Methods: 30 healthy patients scheduled for cesarean section were given local anesthetics epidurally for surgical anesthesia. After delivery of the baby, transdermal scopolamine patch($Kimite^{(R)}$ Myung Moon Pharm. Co., Seoul, Korea) was applied to the study group(n=15) and placebo patch to the control group(n=15). Postoperative analgesia was provided soley with epidural morphine. Nausea was treated with metoclopramide. Results: During 24 hours postoperatively, the mean nausea score was significantly lower in the study group than in the control group. But the nausea incidence was not significantly different between the two groups. The mean number of times antiemetic drugs which were administered to patients were lower in the study group than in the control group($1.5{\pm}0.5$ vs $3.3{\pm}1.3$, p<0.05). Conclusion: Transdermal scopolamine patch provides antiemetic effect simply, continuously and safely, preventing nausea which could occur during administration of epidural morphine after cesarean section.

• Environmental Engineering Research
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• v.17 no.1
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• pp.41-46
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• 2012

In this study, the performance of new digestion system (NDS) for the treatment of food waste leachate was evaluated. The food waste leachate was fed intermittently to an anaerobic reactor at increasing steps of 3.3 L/day (hydraulic retention time [HRT] = 30 day), 5 L/day (HRT = 20 day), and finally 10 L/day (HRT = 10 day). In the anaerobic reactor, the pH and alkalinity were maintained at 7.6 to 8.2 and 8,940-14,400 mg/L, respectively. Maximum methane yield determined to be 0.686L $CH_4$/g volatile solids (VS) containing HRT over 20 day. In the digester, 102,328 mg chemical oxygen demand (COD)/L was removed to produce 350 L/day (70% of the total) of biogas, but in the digested sludge reduction (DSR) unit, only 3,471 mg COD/L was removed with a biogas production of 158 L/day. Without adding any chemicals, 25% of total nitrogen (TN) and 31% of total phosphorus (TP) were removed after the DSR, while only 48% of TN and 32% of TP were removed in the nitrogen, phosphorus, and heavy metals (NPHM) removal unit. Total removal of TN was 73% and total removal of TP was 63%.