• Title/Summary/Keyword: deep donor

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The Mg Solid Solution far the P-type Activation of GaN Thin Films Grown by Metal-Organic Chemical Vapor Deposition

  • Kim, KeungJoo;Chung, SangJo
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.4
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    • pp.24-29
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    • 2001
  • GaN films were grown for various Mg doping concentrations in metal-organic chemical vapor deposition. Below the Mg concentration of 10$^{19}$ ㎤, the thermally annealed sample shows the compensated phase to n-type GaN in Hall measurement. In the MB concentration of 4$\times$10$^{19}$ ㎤ corresponding to the hole carrier concentration of 2.6$\times$1$^{19}$ ㎤ there exists a photoluminescence center of the donor and the acceptor pair transition of the 3.28-eV band. This center is correlated with the defects for a shallow donor of the $V_{Ga}$ and for an acceptor of $Mg_{Ga}$ . The acceptor level shows the binding energy of 0.2-0.25 eV, which was observed by the photon energy of the photocurrent signal of 3.02-3.31 eV. Above the Mg concentration of 4$\times$10$^{19}$ ㎤, both the Mg doping level and Mg concentration were saturated and there Is a photoluminescence center of a deep donor and an acceptor pair transition of the 2.76-eV blue band.

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Surgical Considerations of One-Stage Reconstruction of Large Extremity Defects Using a Thin Deep Inferior Epigastric Perforator Flap

  • Seung Yeol Lee;Moon Chul Seok;Bo Young Park
    • Archives of Plastic Surgery
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    • v.50 no.6
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    • pp.586-592
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    • 2023
  • Background One-stage reconstruction with "thin perforator flaps" has been attempted to salvage limbs and restore function. The deep inferior epigastric perforator (DIEP) flap is a commonly utilized flap in breast reconstruction (BR). The purpose of this study is to present the versatility of DIEP flaps for the reconstruction of large defects of the extremities. Methods Patients with large tissue defects on extremities who were treated with thin DIEP flaps from January 2016 to January 2018 were included. They were minimally followed up for 36 months. We analyzed the etiology and location of the soft tissue defect, flap design, anastomosis type, outcome, and complications. We also considered the technical differences in the DIEP flap between breast and extremity reconstruction. Results Overall, six free DIEP flaps were included in the study. The flap size ranged from 15 × 12 to 30 × 16 cm2. All flaps were transversely designed similar to a traditional BR design. Three flaps were elevated with two perforators. Primary closure of the donor site was possible in all cases. Five flaps survived with no complications. However, partial necrosis occurred in one flap. Conclusion A DIEP flap is not the first choice for soft tissue defects, but it should be considered for one-stage reconstruction of large defects when the circulation zone of the DIEP flap is considered. In addition, this flap has many advantages over other flaps such as provision of the largest skin paddle, low donor site morbidity with a concealed scar, versatile supercharging technique, and a long pedicle.

Autogenous tooth transplantation for replacing a lost tooth: case reports

  • Kang, Ji-Youn;Chang, Hoon-Sang;Hwang, Yun-Chan;Hwang, In-Nam;Oh, Won-Mann;Lee, Bin-Na
    • Restorative Dentistry and Endodontics
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    • v.38 no.1
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    • pp.48-51
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    • 2013
  • The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site.

Photoluminescence Properties of $CuGaSe_2$ Single Crystal ($CuGaSe_2$ 단결정의 Photoluminescence 특성)

  • 진문석;김화택
    • Journal of the Korean Vacuum Society
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    • v.2 no.3
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    • pp.294-298
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    • 1993
  • CuGaSe2 단결정을 고순도(99.9999%)의 Cu, Se 원소를 화학조성비로 칭량한 후 Se을 3mole% 과잉으로 첨가하여 합성된 ingot를 사용하여 iodine(99.9999%)을 수송매체로 한 화학수송법으로 성장시켰다. 성장된 단결정은 검정색을 띠고 있었으며, 10K에서 optical energy gap이 1.755eV로 주어졌다. Ar-ion laser로 여기시켜 측정한 photoluminescence(PL) 스펙트럼으로부터 1.667eV, 1.085eV, 1.025eV에 위치한 세 개의 PL peak를 얻었다. Thermally stimulated current(TSC) 측정에서 0.660eV, 0.720eV의 deep donor level을 관측하였으며, PL peak intensity의 thermal quenching으로 구한 activation energy는 0.010eV이었다. CuGaSe2 단결정에서 PL mechanism은 edge emission 및 donor-acceptor pair recombination임을 규명했다.

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Vapor Phase Epitaxial Growth and Properties of GaN (GaN의 기상성장과 특성)

  • 김선태;문동찬
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.05a
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    • pp.72-75
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    • 1996
  • A hydride vapor phase epitaxy (HVPE) method is performed to prepare the GaN thin films on c-plane sapphire substrate. The full-width at half maximum of double crystal X-ray rocking curves from 20$\mu\textrm{m}$-thick GaN was 576 arcsecond. The photoluminescence spectrum measured 10 K shows the hallow bound exciton (I$_2$) line and weak donor-acceptor peak, however, there was not observed deep donor-acceptor pair recombination indicate the GaN crystals prepared in this study are of high purity and high crystalline quality. The GaN layer is n-type conducting with electron mobility of 72 $\textrm{cm}^2$/V$.$sec and with carrier concentration of 6 x 10$\^$18/cm/sup-3/.

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Breast Reconstruction with Microvascular MS-TRAM and DIEP Flaps

  • Chang, David W.
    • Archives of Plastic Surgery
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    • v.39 no.1
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    • pp.3-10
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    • 2012
  • The free muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) and deep inferior epigastric perforator (DIEP) flaps involve transferring skin and subcutaneous tissue from the lower abdominal area and have many features that make them well suited for breast reconstruction. The robust blood supply of the free flap reduces the risk of fat necrosis and also enables aggressive shaping of the flap for breast reconstruction to optimize the aesthetic outcome. In addition, the free MS-TRAM flap and DIEP flap require minimal donor-site sacrifice in most cases. With proper patient selection and safe surgical technique, the free MS-TRAM flap and DIEP flap can transfer the lower abdominal skin and subcutaneous tissue to provide an aesthetically pleasing breast reconstruction with minimal donor-site morbidity.

Properties of thick-film GaN on sapphire substrates by HVPE method (HVPE 법으로 사파이어 기판 위에 성장한 후막 GaN의 특성)

  • 이영주;김선태
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.37-39
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    • 1996
  • A hydride vapor phase epitaxy (HVPE) method was performed to prepare the GaN thick-films on c-plane sapphire substrates. The full-width at half maximum of double crystal X-ray rocking curve from 350${\mu}{\textrm}{m}$ thick GaN was 576 arcsecond. The photo- luminescence spectrum measured (at room temperature) show the narrow bound exciton(I$_2$) line and weak donor-acceptor pair recombination peak, however, there was not observed deep donor-acceptor pare recombination indicate the GaN crystals prepared in this study are of high purity and high crystalline quality.

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Properties of Substrate-free GaN Grown on AIN/Si by HVPE (HVPE법으로 AIN/Si 기판 위에 성장한 Substrate-free GaN의 특성)

  • 이영주;김선태;정성훈;문동찬
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.194-197
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    • 1997
  • A hydride vapor phase epitaxy (HVPE) method was performed to prepare the thick-fi lm GaN on AIN/Si substrates. We obtained substrate-free GaN. The foul t-width at half maximum of double crystal X-ray rocking curve from 350 ${\mu}{\textrm}{m}$ thick substrate-free GaN was ~1000 arcsec. The photoluminescence spectrum (at 20 K) shows the narrow bound exiton (I$_2$) line and wealth donor-acceptor pair recombination however. there was not observed deep donor-accepter pair recombination indicate the substrate-free GaN crystal prepared in this study are of high purity and high crystalline quality.

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"Mini-Flow-Through" Deep Inferior Epigastric Perforator Flap for Breast Reconstruction with Preservation of Both Internal Mammary and Deep Inferior Epigastric Vessels

  • Satake, Toshihiko;Sugawara, Jun;Yasumura, Kazunori;Mikami, Taro;Kobayashi, Shinji;Maegawa, Jiro
    • Archives of Plastic Surgery
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    • v.42 no.6
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    • pp.783-787
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    • 2015
  • This procedure was developed for preservation of the rectus muscle components and deep inferior epigastric vessel after deep inferior epigastric perforator (DIEP) flap harvesting. A 53-year-old woman with granuloma caused by silicone injection underwent bilateral nipple-sparing mastectomies and immediate reconstruction with "mini-flow-through" DIEP flaps. The flaps were dissected based on the single largest perforator with a short segment of the lateral branch of the deep inferior epigastric vessel that was transected as a free flap for breast reconstruction. The short segments of the donor deep inferior epigastric vessel branch are primarily end-to-end anastomosed to each other. A short T-shaped pedicle mini-flow-through DIEP flap is interposed in the incised recipient's internal mammary vessels with two arterial and four concomitant venous anastomoses. Although it requires multiple vascular anastomoses and a short pedicle for the flap setting, the mini-flow-through DIEP flap provides a large pedicle caliber, enabling safer microsurgical anastomosis and well-vascularized tissue for creating a natural breast without consuming time or compromising the rectus muscle components and vascular flow of both the deep inferior epigastric and internal mammary vessels.

Immediate Bilateral Breast Reconstruction with Unilateral Deep Superior Epigastric Artery and Superficial Circumflex Iliac Artery Flaps

  • Hansen, Keith S.;Gutwein, Luke G.;Hartman, Brett C.;Sood, Rajiv;Socas, Juan
    • Archives of Plastic Surgery
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    • v.43 no.5
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    • pp.457-460
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    • 2016
  • Autologous breast reconstruction utilizing a perforator flap is an increasingly popular method for reducing donor site morbidity and implant-related complications. However, aberrant anatomy not readily visible on computed tomography angiography is a rare albeit real risk when undergoing perforator flap reconstruction. We present an operative case of a patient who successfully underwent a bilateral breast reconstruction sourced from a unilateral abdominal flap divided into deep superior epigastric artery and superficial circumflex iliac artery flap segments.