• Title/Summary/Keyword: Overgrowth

검색결과 216건 처리시간 0.036초

Chloride VPE 법에 의한 메사 구조위에 InP 전류 차단막의 선택적 재성장 (Selective regrowth of InP current blocking layer by chloride vapor phase epitaxy on mesa structures)

  • 장영근;김현수;최훈상;오대곤;최인훈
    • 한국진공학회지
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    • 제8권3A호
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    • pp.207-212
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    • 1999
  • Undoped InP epilayers with high purity were grown by using $In/PCl_3/H_2$ chloride vapor phase epitaxy. It was found that the growth of InP homoepitaxial layer is optimized at the growth temperature of $630^{\circ}C$ and at the $PCl_3$ molar fraction of $1.2\times10^{-2}$. The carrier concentration of InP epilayer was less than $10^{14} {cm}^{-3}$ from the low temperature (11K) photoluminescence measurement. Growth behavior of undoped InP current blocking layer on reactive ion-etched (RIE) mesas has been investigated for the realization of 1.55 $\mu \textrm m$buried-heterostructure laser diode (BH LD), using chloride vapor phase epitaxy. On the base of InP homoepitaxy, InP current blocking layers were grown at the growth temperatures ranging from $620^{\circ}C$ to $640^{\circ}C$. Almost planar grown surfaces without edge overgrowth were achieved as the growth temperature increased. It implied that higher temperature enhanced the surface diffusion of the growth species on the {111} B planes and suppressed edge overgrowth.

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Membrane fouling and sludge characteristics in submerged membrane bioreactor under low temperature

  • Yuan, Yuan;Zhang, Jianqiao
    • Membrane and Water Treatment
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    • 제10권5호
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    • pp.331-338
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    • 2019
  • This study aimed to investigate the membrane fouling and sludge characteristics in a pilot-scale submerged membrane bioreactor (MBR) operated under low temperature ($7^{\circ}C$). To elucidate the mechanisms of membrane fouling at low temperature, we studied the correlation between MBR performances and physicochemical properties of sludge including extracellular polymeric substance (EPS), relative hydrophobicity (RH) and floc size during long-term operation. The MBR was shown able to remove chemical oxygen demand (COD) stably and efficiently (>90 %) in the case of overgrowth of filamentous bacteria (bulking sludge) at low temperature. On the other hand, the occurrence of filamentous bulking greatly accelerated membrane fouling, as indicated by membrane filtration period of 14 days for filamentous bulking at $7^{\circ}C$, in comparison with that of 27 days for non-bulking sludge at $24^{\circ}C$ The overgrowth of filamentous bacteria resulting from low-temperature condition led to an increased release of EPS, higher RH, smaller floc size and lower fractal dimension of sludge. These factors accelerated the formation of compact cake layer on membrane surface in association with performance diminution in terms of increase in transmembrane pressure (TMP) of the membrane and thus the decrease in membrane permeability.

Cochlear Implantation via the Transmeatal Approach in an Adolescent with Hunter Syndrome-Type II Mucopolysaccharidosis

  • Kim, Hantai;An, Jun Young;Choo, Oak-Sung;Jang, Jeong Hun;Park, Hun Yi;Choung, Yun-Hoon
    • 대한청각학회지
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    • 제25권1호
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    • pp.49-54
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    • 2021
  • Type II mucopolysaccharidosis (MPS II) commonly known as Hunter syndrome, is a rare X-linked lysosomal storage disorder caused by iduronate-2-sulfatase deficiency, which in turn causes otorhinolaryngological manifestations, including sensorineural hearing loss (SNHL). Previously, the median survival age of patients with MPS was approximately 13.4 years. However, in the era of enzyme replacement therapy and other multidisciplinary care modalities, the life expectancy has increased. Herein, we report a rare case of an adolescent with MPS II who underwent SNHL treatment with cochlear implantation (CI). Based on unexpected findings of mastoid emissary veins and overgrowth of the vessels around the temporal bone, CI was performed using the transmeatal approach instead of the conventional transmastoid method, to avoid damage to the vessels. The average hearing threshold after CI was 35 dB and no surgical complications were encountered. Adolescent MPS II may present vessel abnormalities, which can reduce the success rate of surgery. In patients with MPS II with SNHL, CI should be performed under careful monitoring of vessel overgrowth. Moreover, with regard to feasibility of CI in adolescent patients with MPS II with SNHL, surgical techniques such as the transmeatal approach should be selected based on adequate assessment of the case.

Cochlear Implantation via the Transmeatal Approach in an Adolescent with Hunter Syndrome-Type II Mucopolysaccharidosis

  • Kim, Hantai;An, Jun Young;Choo, Oak-Sung;Jang, Jeong Hun;Park, Hun Yi;Choung, Yun-Hoon
    • Journal of Audiology & Otology
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    • 제25권1호
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    • pp.49-54
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    • 2021
  • Type II mucopolysaccharidosis (MPS II) commonly known as Hunter syndrome, is a rare X-linked lysosomal storage disorder caused by iduronate-2-sulfatase deficiency, which in turn causes otorhinolaryngological manifestations, including sensorineural hearing loss (SNHL). Previously, the median survival age of patients with MPS was approximately 13.4 years. However, in the era of enzyme replacement therapy and other multidisciplinary care modalities, the life expectancy has increased. Herein, we report a rare case of an adolescent with MPS II who underwent SNHL treatment with cochlear implantation (CI). Based on unexpected findings of mastoid emissary veins and overgrowth of the vessels around the temporal bone, CI was performed using the transmeatal approach instead of the conventional transmastoid method, to avoid damage to the vessels. The average hearing threshold after CI was 35 dB and no surgical complications were encountered. Adolescent MPS II may present vessel abnormalities, which can reduce the success rate of surgery. In patients with MPS II with SNHL, CI should be performed under careful monitoring of vessel overgrowth. Moreover, with regard to feasibility of CI in adolescent patients with MPS II with SNHL, surgical techniques such as the transmeatal approach should be selected based on adequate assessment of the case.

토마토 육묘 시 물리적 자극 및 약제 처리가 묘의 소질과 수량에 미치는 영향 (Effects of Mechanical Stimulation and Chemical Treatments on Growth of Seedlings and Yield of Tomato)

  • 최영하;이한철;박동금;권준국;이재한
    • 원예과학기술지
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    • 제19권3호
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    • pp.320-324
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    • 2001
  • 고온기 토마토(cv. House-momotaro)육묘 시에 묘의 도장을 방지하기 위해 물리적 자극방법으로 Impedance와 Brushing 처리를, 화학약제로는 Diniconazole과 Hexaconazole을 이용하여 묘의 생육조절 효과 및 정식 후의 생육 및 수량에 미치는 영향을 조사하였다. Diniconazole 처리에 의해 육묘 시의 묘의 초장, 엽면적, 생체중 등이 감소되었다. Diniconazole I 처리구에서는 정식 후 생육이 억제되고 수량이 감소되었으나 Diniconazole II 처리구에서는 Control과 비슷한 생육과 수량성을 보였다. Hexaconazole 처리는 묘의 초장을 감소시키나 Diniconazole 처리에 비해 그 정도가 약하였다. 정식 후의 생육은 Control과 큰 차이가 없었으나 착과수가 적고 기형주 발생이 많아 수량이 적었다. Impedance 처리 또한 묘의 초장을 감소시켰으나 정식 후 수확개시기가 늦고 기형주 발생이 많아 수량이 적었다. Brushing 처리는 묘의 초장만 감소시킬 뿐 정식 후 생육 및 수량은 Control과 차이가 거의 없었다. 따라서 Diniconazole의 적절한 사용(Diniconazole II)과 Brushing 처리는 토마토의 수량을 크게 감소시키지 않고 묘의 도장을 억제시킬 수 있어 실용성을 기대할 수 있었다.

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UV-B와 생장억제제 처리가 과채류 플러그 묘의 도장 억제와 정식 후 생육 및 수량에 미치는 영향 (Effects of UV-B and Growth Inhibitor on Overgrowth Retardation and Growth and ield after Planting in Fruit-Vegetable Plug Seedlings)

  • 권준국;이재한;최영하;유인호;황갑춘
    • 생물환경조절학회지
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    • 제12권4호
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    • pp.252-258
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    • 2003
  • UV-B(4 kJ${\cdot}m^{-2}{\cdot}d^{-1}$) 조사와 생장억제제(50 mg${\cdot}L^{-1}$ diniconazole, 500 mg${\cdot}L^{-1}$) 처리가 오이, 토마토 및 고추 플러그 묘의 도장 억제와 정식 이후의 생육과 수량에 미치는 효과를 비교하였다. 플러그 묘의 경장은 UV-B와 diniconazole 처리에서 무처리에 비해 각각 오이 38, 35%, 토마토 37, 41%, 고추 23. 23% 억제되었으며 hexaconaxole,은 억제효과가 낮았다. 그리고 엽면적과 건물중도 UV-B와 생장억제체 처리에 의해 감소되엇다. 뱐면 잎 두께는 UV-B와 생장억제제 처리에 으해 두꺼워지는 경향이었다. 건묘지수는 3작물 모두 UV-B와 생장억제제 처리에 의해 증가외었고 특히 diniconazole와 UV-B 처리가 Hexxonazoile처리에 비해 더 높았다. UV-V를 처리한 플러그 묘는 3작물 모두 정식 시에는 무처리에 비해 초장, 엽면적 등이 짧고 작았으나 정식 후 20-30 일경에는 무처리와 비슷한 수준으로 회복되었다. 이에 반해 생장억제제를 처리한 묘는 회복이 늦어 UV-B 처리한 것에 비해 생장이 저조하였다. 과실 수랴은 오이의 경우 처리간에 차이가 없었으나 토마토와 고추 UV-B를 처리한 것이 생장억제제를 처리한 것에 비해 다소 맣았다. 따라서 UV-B 조사는 과채류 플러그 묘의 도장 억제를 위한 환경 친화적인 방법으로서 이용될 수 있음을 시사해주었다.

InGaAs/AlGaAs 양자선 래이저에서 관찰된 이상 방출 스펙트럼 (Anomalous Emission Spectra Observed in InGaAs/AlGaAs Quantum-Wire Lasers)

  • 김경찬;김태근
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 C
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    • pp.2020-2021
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    • 2004
  • Distributed optical feedback by gain coupling in V-groove quantum-wire lasers is investigated using InGaAs/AlGaAs active materials grown by metalorganic chemical vapor deposition (MOCVD). In order to avoid grating overgrowth during the fabrication of DFB structures, a newly developed constant MOCVD growth method is employed. Gain anisotropy in emission spectra near Bragg wavelength, resulting from optical feedback along the DFB direction, is clearly observed at room temperature.

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종격동 cystic hygroma 1례 보고 (Mediastinal cystic hygroma: A report of one case)

  • 김용진;양승하
    • Journal of Chest Surgery
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    • 제15권3호
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    • pp.299-302
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    • 1982
  • Cystic hygroma is benign overgrowth of the lymphatic vessels and is usually located in the neck, but rare in the mediastinum. This vascular tumor may appear in any portion of mediastinum, but seems to be most common anteriorly. This is a report of one case of congenital mediastinal cystic hygroma in a 25 years old man, especially in the thymic location which was surgically removed successfully with good postoperative result and confirmed histopathologically.

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척추 경막외 지방종증 -증례보고- (Spinal Epidural Lipomatosis -A case report-)

  • 김세영
    • The Korean Journal of Pain
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    • 제22권3호
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    • pp.249-252
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    • 2009
  • Spinal epidural lipomatosis (SEL) is a rare condition of pathological overgrowth of fat tissue in the vertebral canal. SEL leads to back pain, radiculopathy or paraparesis. Glucocorticoids seem to play a major role in the development of SEL. SEL is best diagnosed by magnetic resonance imaging. The treatment of SEL is directed at reducing the body weight and decreasing the excess glucocorticoid. In severe cases, decompressive laminectomy with removal of the excess epidural fat might become necessary to alleviate the neurological symptoms caused by spinal cord compression.