• 한국주조공학회지
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• 제7권2호
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• pp.122-132
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• 1987

Full mold casting process is a new technique offering numerous advantages and promising possibilities. The present study is aimed to bring out the results of experiments carried out to study the effect of pattern coatings on the solidification of 99.5% pure aluminum plate-shaped castings in the various sand molds and the thermal behavior of the molds. The results of the investigation indicate that (i) with increase in pattern coating thickness, the relative chilling power decreases gradually for silica and increases for zircon coating, and (ii) the application of a pattern coating significantly reduces the maximum interface temperature by the mold which is more pronounced in the case of thinner mold wall. The investigation also indicates that Chvorinov's rule is not found to be valid for the casting in the full mold, with or without pattern coating. Therefore in full mold process, the pattern coating thickness will be a very important parameter in the study of thermal behavior.

• Structural Engineering and Mechanics
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• 제7권4호
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• pp.377-386
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• 1999

The stress distribution in a symmetrically laminated composite plate subjected to in-plane compression are evaluated using finite element analysis. Six different finite element models are created for the study of stresses in the plate after buckling. Two finite element modelling approaches are adopted to obtain the stress distribution. The first approach starts with a full model of shell elements from which sub-models of solid elements are spin-off The second approach adopts a full model of solid elements at the beginning from which sub-models of solid elements are created. All sub-models have either 1-element thickness or 14-element thickness. Both techniques show high interlaminar direct and shear stresses at the free edges. The study also provides vital information of the distribution of all components of stresses along the unloaded edges in length direction and also in the thickness direction of the plate.

• Archives of Plastic Surgery
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• 제37권5호
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• pp.589-594
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• 2010

Purpose: Full thickness skin grafts are useful in the reconstruction of facial skin defects when primary closure is not feasible. Although the supraclavicular area has been considered as the choice of donor site for large facial skin defect, many patients are reluctant to get a neck scar and some patients do not have enough skin to cover the defect owing to the same insult occurred to the neck such as burn accident. We present several cases of reconstruction of facial skin defects by freehand full-thickness skin graft from anterolateral chest wall resulting aesthetically acceptable outcome with lesser donor site morbidity. Methods: Retrospective review was performed from March, 2007 to September, 2009. 15 patients were treated by this method. Mean age was 31.5 years. The ethiology was congenital melanocytic nevus in 7 cases, capillary malformation in 5 cases and burn scar contracture in 3 cases. Mean area of lesion was measured to 67.3 cm2 preoperatively. The lesion was removed beneath the subcutaneous fatty tissue layer. The graft was not trimmed to be thin except defatting procedure. For the larger size of defect, two pieces of grafts were harvested from both anterolateral chest wall in separation and combined by suture. Results: The mean follow up period was 9.7 months. All the grafts survived without any problem except small necrotic areas in 4 cases, which healed spontaneously under conventional dressings in 6 weeks postoperatively. Color match was relatively excellent. There were 2 cases of hyperpigmentation immediately, but all of them disappeared in a few months. Conclusion: In cases of large facial skin defects, the anterolateral chest wall may be a good alternative choice of full-thickness skin graft.

• 대한수의학회지
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• 제40권3호
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• pp.497-504
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• 2000

To document that effects of hyperbaric oxygen(HBO) and ${\alpha}-tocopherol$ on full-thickness skin grafts in rat, we performed full-thickness skin grafts bilaterally on each rats. The HBO-treated rats were received HBO twice daily for 90 minutes at 2 ATA. Surgical control rats were not treated with HBO. ${\alpha}-tocopherol$ treated rats were received the agent via oral gastric tube daily for 3 days preoperative and a fourth dose 1 to 2 hours postoperative. HBO plus ${\alpha}-tocopherol$ treated rats were received HBO and ${\alpha}-tocopherol$ as mentioned above. Biopsy specimens were taken from each rat at the time of grafting and on days 2, 4, 7, 10, 14, 21, and 28, then were processed for tissue-concentration of total glutathione(GSHt), oxidized/reduced glutathione level, and thiobarbituric acid-reactive substance(TBARS) levels. The percentage of viable graft on day 10 ranged from 67 to 93%, and was not significantly different among the each other groups. The percentage of viable graft were, however, higher in HBO plus ${\alpha}-tocopherol$ treated rats(78.6%) than in HBO alone treated rats(59.1%), ${\alpha}-tocopherol$ alone treated rats(66.7%) and surgical control rats(58.2%). TBARS concentration had a significant increase from preoperative concentration at day 2, and peak concentration at day 4(p<0.01). Concentration then decreased to preoperative concentration at day 28. GSHt concentration of free skin graft had a similar patteren of change in four groups and decreased significantly from preoperative concentration at day 2, returning to preoperative concentration by day 7(surgical control, HBO-treated, and ${\alpha}-tocopherol-treated$, alone) and 28(HBO plus ${\alpha}-tocopherol-treated$). Percentage of the concentration of reduced glutathione decreased in surgical control, HBO-treated and, ${\alpha}-tocopherol-treated$(p<0.05), and HBO plus ${\alpha}-tocopherol-treared$(p<0.01) on day 7 after surgery, whereas the concentration of oxidized increased significantly in HBO-treated(p<0.05), ${\alpha}-tocopherol-treated$(p<0.05), and HBO plus ${\alpha}-tocopherol-treated$(p<0.01).

• Clinics in Shoulder and Elbow
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• 제13권1호
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• pp.79-85
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• 2010

목적: 견갑하근 상부의 완전 파열 시 봉합나사를 이용한 파열 부 봉합술과 변연절제술을 비교하여 보고자 한다. 대상 및 방법: 2003년 5월부터 2007년 10월까지 본원에서 견갑하근 상부의 완전 파열에 대해 봉합나사를 이용한 관절경 감시하의 봉합술을 시행한 69예와 변연절제술을 시행한 30예의 환자를 대상으로 하였다. 견갑하근 손상의 범위는 상부 1/3인 경우를 대상으로 하였다. 결과의 판정은 최초 내원 시점과 최종 추시의 UCLA 와 ASES 중 일상생활지수 (ADL)과 통증 점수를 비교하였다. 결과: 1군과 2군 모두 UCLA, ASES score, ASES score 중 통증에 대한 VAS 점수, 5점을 만점으로 한 내 회전 근력평가평가에서 술 전 보다 술 후 결과가 향상되었다. 1군과 2군의 비교에서 술 후 UCLA 및 VAS 점수는 p>0.05로 차이가 없었고, ASES점수 및 내 회전 근력에 대한 평가는 p<0.05로 의미 있는 차이가 있었다. 결론: 견갑하근의 상부 완전파열 시 견갑하근 봉합술은 단순 변연절제술보다 좋은 치료방법으로 고려할 수 있다.

• 대한관절경학회지
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• 제17권1호
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• pp.1-5
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• 2013

목적: 저자들은 회전근개 전층 파열 환자에 대하여 관절경적 Ulsan University - Mason Allen - Suture Bridge (UU MA SB) 봉합법을 시행한 후 임상 결과를 분석하였다. 대상 및 방법: 2010년 9월부터 2010년 12월까지 회전근개 전층 파열을 관절경적 UU MA SB 봉합법으로 치료받은 15예를 대상으로 하였다. 술전, 12주, 6개월 추시 시 Korean shoulder score (KSS), American shoulder and elbow surgeon(ASES), University of California, Los Angeles (UCLA), visual analogue scale (VAS), 관절운동 범위측정을 이용한 평가를 시행하였다. 결과: 최종 추시 결과 술전 평균 KSS $51.4{\pm}13.0$에서 $92.0{\pm}6.9$으로 호전되어 유의한 차이(p<0.05)를 보였으며, ASES score 역시 평균 $15.9{\pm}6.5$에서 $27.1{\pm}2.4$로 호전되어 유의한 차이(p<0.05)를 보였다. UCLA score $15.1{\pm}3.9$에서 $31.9{\pm}3.6$으로, VAS $7.2{\pm}2.3$에서 $0.9{\pm}1.2$로 술전보다 술후 결과가 유의하게(p<0.05) 향상되었다. 결론: 회전근개 전층파열 환자에서 관절경적 UU MA SB 봉합술을 시행하여 동통의 감소 및 견관절 기능 향상의 우수한 결과를 얻을 수 있었다.

• 디지털융복합연구
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• 제12권8호
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• pp.303-308
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• 2014

본 논문은 스마트폰의 후면에 페라이트 시트를 종류별, 패턴별, 두께별로 부착하여 NFC의 인식거리를 시뮬레이션을 통하여 최적의 페라이트 시트를 설계하였다. 패턴별 특징은 I-type보다는 Full- type의 통신거리가 1~2mm 정도 더 확장되었다. 적용한 페라이트 시트는 금속에 의한 NFC 안테나의 특성을 개선하는 효과를 확인하였으며, 패턴 C의 경우 투자율이 140, 두께가 0.1mm, Full-type 인 페라이트 시트를 적용하였을 때 NFC 통신거리가 일반 전자파 흡수제의 경우 45mm에서 59mm로 증대되었음을 확인하였다.

• Clinics in Shoulder and Elbow
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• 제10권1호
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• pp.42-49
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• 2007

목적: 회전근 개 전층 파열의 봉합술 후 회전근 개의 두께를 자기 공명 영상에서 측정하여 파열이 없는 젊은 층 및 장노년층 대조군과 비교하고 술 전 파열의 정도와의 상관 관계를 알아보고자 하였다. 대상 및 방법: 본원에서 시행한 회전근 개 전층 파열에 대한 봉합술 시행 후 자기 공명 영상을 시행하였던 19예의 환자($45{\sim}77$세, 평균 63.3세)를 제 1군, 파열이 없는 환자들 중 제 1군과 비슷한 장,노년기 환자 23예를 제 2군($46{\sim}69$세, 평균 57.9세), 30세 이하의 청년기 환자 22예를 제 3군($18{\sim}30$세, 평균 23.3세)으로 하여 각 군의 회전근 개의 두께를 비교하였다. 제 1군에서 파열의 길이는 자기 공명 관절 조영술 사위 관상면 영상에서, 넓이는 사위 시 상면에서 측정하여 그 중 큰 값을 파열의 크기로 하였고, 회전근 개의 두께는 관절와 후외연으로부터 전방 15 mm 지점의 사위 관상면에서 측정하였다. 또한, 제 1군의 파열의 크기와 술 후 회전근 개의 두께와의 상관 관계를 알아보았다. 결과: 제 1군의 술 후 회전근 개의 평균 두께는 3.0 mm였고, 술 전 파열의 크기와 회전근 개의 두께는 반비례하였으며(P<0.001), 제 2군, 제 3군의 회전근 개의 두께는 각각 3.9 mm, 5.0 mm로 세 군의 두께가 통계적으로 유의한 차이를 보였다(P<0.05). 결론: 회전근 개의 두께는 연령이 많을수록 작았고 전층 파열 봉합술 후 두께는 술 전 파열의 크기와 반비례하였으며 정상군에 비해 작았다.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권3호
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• pp.106-110
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• 2004

The operating condition of the OLED (organic light-emitting diode) is very sensitive to electrode thickness properties. The electrode thickness is a significant issue in the construction of OLEDs because of its transparency, high conductivity and high efficiency as an injector into organic materials. We carried out a systematic study to optimize the electrode thickness conditions in Indiumtin oxide (ITO), Molybdenum (Mo) and Aluminum (Al). Further, we measured electrode thickness under standard conditions [ITO 1500$\AA$, Mo 2600$\AA$, Al 1500$\AA$]. We also evaluated power consumption. In addition, we analyzed substrate uniformity with IVL measurement results. From these results, it is known that the electrode thickness should be optimized in order to accomplish optimal power efficiency.

• Archives of Plastic Surgery
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• 제40권1호
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• pp.11-18
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• 2013

Background To minimize the inflammatory reaction and improve healing, a new modified dermal substitute composed of an atelocollagen, chondroitin-6-sulfate, and amniotic membrane (AM) was applied to full-thickness skin defects in a pig. Atelocollagen was extracted from bovine skin, and two modified dermal substitutes were generated according to the cross-linking type. Methods The AM-collagen dermal substitutes were characterized and compared with currently used dermal substitutes in a pig skin defect model. There were five experimental groups: dehydrothermal (DHT) cross-linking atelocollagen with the AM on the top (AM-DHT), DHT and chemical cross-linking atelocollagen with the AM on the top (AM-DHT/chemical), Terudermis, Integra, and AlloDerm. After $3{\times}3cm$ full-thickness skin defects on the back of a pig were created, each dermal substitutes dermal substitutes was randomly grafted on the defects. Two weeks after grafting, autologous partial-thickness skin was over-grafted on the neodermis. The take rate of the dermal substitutes, skin, and histological sections were all assessed at 1, 2, and 4 weeks postoperatively. Results More rapid healing and a higher take rate were evident in the AM-DHT and Terudermis groups. Histological examination revealed fewer inflammatory cells and more fibroblast hyperplasia in these two groups. Four weeks after surgery, the amount of newly formed collagen was significantly more appropriate in the AM-DHT group. Conclusions These observations provide supporting evidence that a newly developed amniotic-collagen dermal substitute may inhibit inflammatory reactions and promote wound healing.