• Journal of the Korean Chemical Society
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• v.31 no.6
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• pp.498-502
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• 1987

Electrical conductivities of $(ZrO_2)_x-(Tm_2O_3)_y$ systems containing 1, 3 and 5mol% of $ZrO_2$ have been measured as a function of temperature and of oxygen partial pressure at temperatures from 600 to 1,100$^{\circ}$C and oxygen partial pressures from $10^{-5}$ to $2{\times}10^{-1}atm$. Plots of log conductivity vs. 1/T are found to be linear and average activation energy is 1.51 eV. The electrical conductivity dependences on PO$_2$ are different at two temperature regions, indicating ${\sigma}{\alpha}PO_2^{1/5.3}$ and ${\sigma}{\alpha}PO_2^{1/10.7}$ at high-and low-temperature regions, respectively. The defect of $(ZrO_2)_x-(Tm_2O_3)_y$ system is $V_{Tm}^{'''}$ and an electron hole is suggested as a carrier at high temperature region. At low temperature region, a mixed ionic and hole conduction is reasonable.

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.52-59
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• 2007

Purpose: The venous flap is used as an alternative method to the standard free flap for the management of small and thin soft tissue defects. Especially, the venous flap has advantages of being thin, easy harvest and various donor sites, as well as it having lower morbidity. Yet their clinical applications have been limited by their unstable postoperative course and also by their complications such as partial necrosis. The aim of this study is to extend the clinical indications of venous flaps with using various methods. Methods: From May 2005 to March 2006, total of 19 patients(21 cases) underwent various venous flaps for soft tissue defects as a result of trauma(15 cases), facial skin cancer(3 cases), chronic ulcer(1 case) and surgical wound for congenital anomaly(2 cases). The arterialized venous free flap were applied in 18 cases, the pure venous free flap was applied in 1 case and the pure venous pedicled flap were applied in 2 cases. Among them, two flow-through arterialized venous free flaps were applied that used the great saphenous vein to reconstructed major arteries as well as the injured skin and soft tissues in the arm. All the flap were harvested from the volar wrist(11 cases), dorsum of foot(5 cases), thenar(2 cases), and medial thigh(3 cases). Results: The sizes of the flap ranged from $0.75cm^2$ to $264cm^2$(mean size: $40.06cm^2$). The follow-up period ranged from two to twelve months. In the majority of cases, we obtained satisfying results, which was the excellent reconstruction of skin and soft tissue defects and especially in the case of limb salvage, replantation and cancer reconstruction. However, there were 5 cases of partial necrosis and 2 cases of complete failure. The donor sites were closed primarily in 7 cases and wound closure with skin graft were in 14 cases. Conclusion: We conclude that the venous flap will not only be useful for reconstruction of small defect in the hand and foot, but also be useful for various other clinical indications.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.80.1-80.1
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• 2010

A strontium titanate ($SrTiO_3$)-based material with a perovskite structure is considered to be one of the promising alternatives to $LaCrO_3$-based materials since $SrTiO_3$ perovskite shows a high chemical stability under both oxidizing and reducing atmospheres at high temperatures. $SrTiO_3$ materials exhibit an n-type semiconducting behavior when it is donor-doped and/or exposed to a reducing atmosphere. In this work, $Sr_{1-x}La_xTi_{1-y}M_yO_3$ materials doped with $La^{3+}$ in A-sites and aliovalent transition metal ions ($M^{n+}$) in B-sites were synthesized by the modified Pechini method. The X-ray diffraction analysis indicated that the materials synthesized by the Pechini process exhibited a single curbic perovskite-type structure without any impurity phases, and are tolerant, to some extent, to cation doping. The sintering behaviors of $Sr_{1-x}La_xTi_{1-y}M_yO_3$ in $H_2/N_2$ and air were characterized by dilatometry and microstructural observations. The electrical conduction mechanism and the dopant effect are discussed based on the defect structures and the electrical conductivities measured at various oxygen partial pressures and temperatures.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.10
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• pp.947-952
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• 2006

It has been confirmed that the inner defect of insulator and the perfect diagnosis for aging are closely related to safe electric power transmission system and that the detection of accident and diagnosis technique turn out to be very important issues. But perfect diagnosis is difficult because discharge pattern is irregular. Thus, we investigated discharge pattern using the new distribution statistical models with cross-inked polyethylene(XLPE) specimens. Voltage was applied to power frequency by step method, and calibration of discharge was set to 50 pC. After the voltage was applied, it measured the discharge occurring during 10s. We investigated discharge pattern using the K-means analysis and Weibull function. We also investigated variation of centroid and shape parameter due to variation of voltage. As a result of analyzing K-means, it was confirmed that cluster including many object numbers was formed by the presence of void. And result of Weibull distribution, it was confirmed that shape parameter of discharge varied from 1.28 to 1.62 in no void specimens, and that shape parameter of discharge number varied from 1.28 to 1.62. In the void, shape parameter of discharge varied from 5.66 to 6.43, and shape parameter of discharge number varied from 5.05 to 5.08.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.6
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• pp.298-302
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• 2014

The radial forearm free flap (RFFF) is a thin and pliable tissue with many advantages for tongue reconstruction. However, tongues reconstructed with RFFF occasionally need revision surgery because inadequate defect measurement at primary surgery can lead to bulkiness and limited movement of reconstructed tongue. In this case, the patient underwent partial glossectomy and RFFF reconstruction for treatment of tongue cancer five years prior. We could not make a lower denture for the patient, because the alveolo-lingual sulcus of tongue was almost lost. So we performed vestibuloplasty with a modified Kazanjian method on the lingual vestibule of the mandibular right posterior area, and defatting surgery to debulk the flap. After surgery, we observed that the color and texture of the revised tongue changed to become similar with adjacent tissue. The patient obtained a more functional and esthetic outcome. Accordingly, we present a case report with a review of relevant literature.

• Archives of Reconstructive Microsurgery
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• v.16 no.1
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• pp.39-47
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• 2007

With the advent of microsurgery, perforator free flap is nowadays considered the first choice for reconstruction of the extensive defect of the extremities because of their moderate thickness. Among them, anterior (anterolateral and anteromedial) thigh perforator free flaps provide the first choice for reconstruction of various soft tissue defects of the extremities with many advantage such as its large, uniform thickness, long vascular pedicle with proper vessel size and minimal donor site morbidity. But, it has still some criticism of unreliable perforators which makes us very careful in elevating the flap. Between March of 2006 and February of 2007, we treated 7 patients of soft tissue defects in the hand and lower extremities with anterior thigh perforator free flap at Hallym and DongGuk University Hospital. We performed 6 anterolateral thigh perforator free flaps based on the descending branch of lateral circumflex femoral artery (LCFA) and 1 anteromedial thigh perforator free flap based on the innominate branch of the LCFA. While approaching for the anterolateral thigh free flap, we happen to meet the cases which we should change into the anteromedial thigh free flap uneventfully on the operating field. In contrast to the original design of anterolateral thigh free flap, we had to harvest the anteromedial thigh perforator free flap in 1 case. All the anterior thigh perforator free flaps survived completely except 1 case of partial necrosis due to venous congestion. Donor sites were closed primarily and healed uneventfully within 2 weeks. Patients were satisfied with the functionally and aesthetically acceptable results. Although doppler sonography is strongly recommended preoperatively in planning the anterior thigh perforator free flaps, we should always remember the variation in vascular anatomy and be ready to change the flap choice from the anterolateral to anteromedial intraoperatively. we provide a review of the literature and present our series of anterior thigh perforator free flaps for reconstruction of the extremities.

• Clinical and Experimental Pediatrics
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• v.52 no.12
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• pp.1388-1391
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• 2009

Poland syndrome is characterized by unilateral absence or hypoplasia of the pectoralis muscle and variable degree of ipsilateral hand anomalies. Mobius syndrome is a congenital neurological disorder characterized by complete or partial facial paralysis. Although the pathogeneses of these diseases are not well-characterized, diminished blood flow to the affected side is thought to play a role. A male infant weighing 2.670 g was born at 38+3 weeks of gestation with left facial paralysis, left chest wall defect with dextrocardia, and symbrachydactyly between the second and third fingers. The combination of Poland-Mobius syndrome is rare, and only 2 cases associated with dextrocardia have been reported worldwide. Here, we report the first case of Poland-Mobius syndrome associated with dextrocardia in Korea.

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.428-434
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• 2005

Extensive and complicated defects on the body call for an omnipotent tool for a perfect reconstruction. Flaps derived from the omentum has many advantages over the conventional flaps. From 1999 to 2004, Omental flaps were applied for various soft tissue reconstructions. Among total 20 total 7 cases were for immediate reconstruction, 2 cases for chronic infection, 3 cases for simultaneous reconstruction of two defects, 4 cases for functional joint reconstruction and 4 cases were for flow- through revascularization. Among these cases, 3 cases were operated with minimal incision harvest technique. There were no complete flap failures, partial necrosis of the distal parts were noted on three cases. The omental flap is indicated on a large contaminated defect reconstruction due to its large size, well-vascularized, and malleable properties. The omental flap provides several additional advantages over other flaps, which are; the availability of the one staged simultaneous reconstruction of two defects with one flap, providing gliding function for the joint motion, and a flow-through characteristics with long vascular pedicle. But there are some serious shortcomings, including a long abdominal scar and intraabdominal problems. However, these are rare and can be minimized with our minimal incision technique. Due to its unique characteristics. the omentum is one of the ideal tissues for the reconstruction of the complicated soft tissue defects due to its unique characteristics.

• Journal of the Korean Chemical Society
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• v.26 no.3
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• pp.128-134
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• 1982

The electrical conductivity of n-type polycrystalline MnOx-Ti$O_2$ system containing 0.40, 0.80, and 1.60 mol % of manganese oxide has been measured from 100 to 400$^{\circ}$C and 1100 to 1300$^{\circ}$C under oxygen partial pressures of$10^{-8}\;to\;10^{-1}$ atm. Plots of log conductivity vs. reciprocals of absolute temperature at constant $Po_2$'s are found to be linear with an inflection, and the activation energies obtained from the slopes appear to be an enough average 0.18eV for the extrinsic and 3.70eV for the intrinsic. The log $\sigma$ vs. log $Po_2$ are found to be linear at $Po_2$'s of $10^{-8}\;to\;10^{-1}$atm. The conductivity dependences on $Po_2$at the two temperature regions are closely approximated by $\sigma{\propto}$Po_2$-1}6$ for the extrinsic and $${\sigma}{\propto}Po_2^{-1}4}$$ for the intrinsic, respectively. The predominant defects are believed to be Vo-2e' and $Ti^3$${\cdot}$interstitial at the extrinsic and intrinsic. From the interpretations of conductivity dependences on temperature and$Po_2$ , the conduction mechanisms and possible band models are proposed.

• Archives of Plastic Surgery
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• v.44 no.2
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• pp.136-143
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• 2017

Background The goal of this study was to investigate the anatomy of the peroneal artery and its perforators, and to report the clinical results of reconstruction with peroneal artery perforator flaps. Methods The authors dissected 4 cadaver legs and investigated the distribution, course, origin, number, type, and length of the perforators. Peroneal artery perforator flap surgery was performed on 29 patients. Results We identified 19 perforators in 4 legs. The mean number of perforators was 4.8 per leg, and the mean length was 4.8 cm. Five perforators were found proximally, 9 medially, and 5 distally. We found 12 true septocutaneous perforators and 7 musculocutaneous perforators. Four emerged from the posterior tibia artery, and 15 were from the peroneal artery. The peroneal artery perforator flap was used in 29 patients. Retrograde island peroneal flaps were used in 8 cases, anterograde island peroneal flaps in 5 cases, and free peroneal flaps in 16 cases. The mean age was 59.9 years, and the defect size ranged from $2.0cm{\times}4.5cm$ to $8.0cm{\times}8.0cm$. All the flaps survived. Five flaps developed partial skin necrosis. In 2 cases, a split-thickness skin graft was performed, and the other 3 cases were treated without any additional procedures. Conclusions The peroneal artery perforator flap is a good alternative for the reconstruction of soft tissue defects, with a constant and reliable vascular pedicle, thin and pliable skin, and the possibility of creating a composite tissue flap.