• 제목/요약/키워드: Differential erosion

검색결과 47건 처리시간 0.032초

Molecular Structure and Gelatinization Properties of Turnip Starch (Brassica rapa L.)

  • Kim, Nam-Hee;Yoo, Sang-Ho
    • Food Science and Biotechnology
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    • 제14권4호
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    • pp.470-473
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    • 2005
  • Starch was isolated from turnip (Brassica rapa L.), and to elucidate the structure-function relationship its structural and physical properties were characterized. Morphological structure of the starch was analyzed by SEM (Scanning Electron Microscopy). Most of the starch granules were spherical in shape with diameter ranging from 0.5-10mm. Apart from larger granules ($<10\;{\mu}m$) which dominated the population size of turnip starch, significant amount of small ($0.5-2\;{\mu}m$) and mid-size granules (${\sim}\;{\mu}m$) were also detected. It was revealed that presumably, erosion damages occurred due to the attack of amylase-type enzymes on the surface of some granules. Branch chain-length distribution was analyzed by HPAEC (High-Performance Anion-Exchange Chromatography). The chain-length distribution of turnip starch revealed a peak at DP12 with obvious shoulder at DP18-21. The weight-average chain length ($CL_{avg}$) was 16.6, and a large proportion (11.8%) of very short chains (DP6-9) was also observed. The melting properties of starch were determined by DSC (Differential Scanning Calorimetry). The onset temperature ($T_o$) and the enthalpy change (${\Delta}H$) of starch gelatinization were $50.5^{\circ}C$ and 12.5 J/g, respectively. The ${\Delta}H$ of the retrograded turnip starch was 3.5 J/g, which indicates 28.2% of recrystallization. Larger proportion of short chains as well as smaller average chain-length can very well explain relatively lower degree of retrogradation in turnip starch.

사행하천(蛇行河川)의 횡방향(橫方向) 하상경사(河床傾斜)의 예측모형(豫測模型) (A Prediction Model of Transverse Bed Slope in Meandering Rivers)

  • 홍창선;정용태
    • 대한토목학회논문집
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    • 제11권4호
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    • pp.81-89
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    • 1991
  • 사행하천형의 특성은 유로의 한쪽제방을 침식시키고, 다른 쪽은 퇴적을 일으키므로써 유로위치에 따라 천천히 형성되는데, 본 연구에서는 Odgaard(1986)가 제안한 횡방향 하상경사에 관한 선형 2차 미분방정식에 Langbein & Leopold(1966)가 제안한 sine-generated curve를 도입하므로써 위상차 및 폭-수심비의 영향을 고려한 새로운 하상형을 제시하고, 금강유역에 위치한 청원과 연기지역을 대상하천으로 하상변동조사보고서의 자료를 이용하여 비교분석한 결과 실측치와 잘 일치하였다.

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Pituitary Apoplexy Presenting as Isolated Third Cranial Nerve Palsy with Ptosis : Two Case Reports

  • Cho, Won-Jin;Joo, Sung-Pil;Kim, Tae-Sun;Seo, Bo-Ra
    • Journal of Korean Neurosurgical Society
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    • 제45권2호
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    • pp.118-121
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    • 2009
  • Pituitary apoplexy is a clinical syndrome caused by an acute ischemic or hemorrhagic vascular accident involving a pituitary adenoma or an adjacent pituitary gland. Pituitary apoplexy may be associated with a variety of neurological and endocrinological signs and symptoms. However, isolated third cranial nerve palsy with ptosis as the presenting sign of pituitary apoplexy is very rare. We describe two cases of pituitary apoplexy presenting as sudden-onset unilateral ptosis and diplopia. In one case, brain magnetic resonance imaging (MRI) revealed a mass in the pituitary fossa with signs of hemorrhage, upward displacement of the optic chiasm, erosion of the sellar floor and invasion of the right cavernous sinus. In the other case, MRI showed a large area of insufficient enhancement in the anterior pituitary consistent with pituitary infarction or Sheehan's syndrome. We performed neurosurgical decompression via a transsphenoidal approach. Both patients showed an uneventful recovery. Both cases of isolated third cranial nerve palsy with ptosis completely resolved during the early postoperative period. We suggest that pituitary apoplexy should be included in the differential diagnosis of patients presenting with isolated third cranial nerve palsy with ptosis and that prompt neurosurgical decompression should be considered for the preservation of third cranial nerve function.

Probabilistic Prediction of Stability of Ship by Risk Based Approach

  • Long, Zhan-Jun;Lee, Seung-Keon;Lee, Sung-Jong;Jeong, Jae-Hun
    • 한국항해항만학회지
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    • 제33권4호
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    • pp.255-261
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    • 2009
  • Prediction of the stability for ships is very complex in reality. In this paper, risk based approach is applied to predict the probability of capsize for a certified ship, which is effected by the forces of sea especially the wave loading Safety assessment and risk analysis process are also applied for the probabilistic prediction of stability for ships. The probability of shipsencountering different waves at sea is calculated by the existed statistics data and risk based models. Finally, ship capsizing probability is calculated according to single degree of freedom(SDF) rolling differential equation and basin erosion theory of nonlinear dynamics. Calculation results show that the survival probabilities of ship excited by the forces of the seas, especially in the beam seas status, can be predicted by the risk based method.

Cystic Giant Sacral Schwannoma Mimicking Aneurysmal Bone Cyst : A Case Report and Review of Literatures

  • Cho, Dong-Young;Hur, Jung-Woo;Shim, Jung-Hyun;Kim, Jin-Sung
    • Journal of Korean Neurosurgical Society
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    • 제54권4호
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    • pp.350-354
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    • 2013
  • To present a rare case of a cystic giant schwannoma of the sacrum mimicking aneurysmal bone cyst (ABC). A 54-year-old man visited our institute complaining left leg weakness and sensory change for several years. Magnetic resonance imaging revealed a large multilocular cystic mass with canal invasion and bone erosion confined to left S1 body. The lesion showed multiple septal enhancement without definite solid component. Initially the tumor was considered as ABC. The patient underwent grossly-total tumor resection with lumbosacral reconstruction via posterior approach. The tumor was proved to be a cystic schwannoma. The postoperative course was uneventful and the patient was relieved from preoperative symptoms. We present a rare case of pure cystic giant schwannoma confined to sacrum mimicking ABC. The surgical treatment is challenging due to the complex anatomy of the sacrum. Schwannoma should be considered in the differential diagnosis of osteolytic sacral cysts.

악관절증에 관한 방사선학적 연구 (RADIOGRAPHIC STUDY ON TEMPOROMANDIBULAR JOINT ARTHROSIS)

  • 유동수
    • 치과방사선
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    • 제10권1호
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    • pp.47-55
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    • 1980
  • The author analysed the routine radiographic changes and clinical symptoms of 205 cases of temporomandibular joint arthrosis. The clinical symptoms of the patients were classified and the morphological ylar head, articular eminence, and articular fossa were analized and discussed view point. The positional changes of condylar head and articular fossa relatation in TMJ arthrosis were observed. The frequencies of coincidence between the site of complaints and the site of the abnormal images which could be detected were examined. The results were obtained as follows; 1. Bone erosion, deformity, marginal proliferation and sclerosis were selected from many abnormal images as the radiographic diagnostic criteria of TMJ arthrotic lesions. 2. Abnormal radiographic findings were revealed in 150 cases (73.9%) of 205 total TMJ arthrosis cases and site with abnormal findings coincided with the site of complaints in 106 cases (70.7%) of 150 cases and coincidence rates were higher above fourth decades than below third decades. 3. Sclerosis of the abnormal radiographic findings could be found more often below third decades than above fourth decades. 4. The positional changes of condylar head were revealed in 176 cases (85.9%) of 205 total cases. 5. Pain complaints were revealed in 170 cases(82.9%) and clicking sounds were revealed in 120 cases (58.6%) of clinical symptoms of TMJ arthrosis. 6. No tendency was found so far the differential diagnosis between pain dysfunction syndrom and osteoarthrosis of TMJ.

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다중계측기법을 이용한 원전 주증기배수밸브의 현상태 누설진단에 관한 연구 (A Study on the As-Built Leakage Diagnosis of Main Steam Drain Valves for Nuclear Power Plants by Multi-measuring Technique)

  • 김성영;김영범;김도형;이상국
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2606-2611
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    • 2008
  • The high energy fluid leakage from the high temperature and high differential pressure drop system of NPPs (Nuclear Power Plants) decreases efficiency and consequently leads to considerable economic loss due to less power production. Also, the leakage possibly damages critical parts of components such as valve and trim with the effect of cavitation, flashing, and erosion, etc. and deteriorates its performance. Thus, in this study, we diagnosed the as-is leakage for four (4) main steam drain valves and two (2) steam traps of Yonggwang 1,2 units during normal operation by using multi-measuring technique and observed the occurrence of fine leakage. In the course of measuring fluid leakage, the sign of fine leakage is estimated to be the leakage from orifice. By converting the leakage to energy loss, it is equivalent to the amount of several hundred thousand won per each unit, which supports the basis for the justification of fine leakage.

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Pott's puffy tumor of the upper eyelid misdiagnosed as simple abscess: a case report and literature review

  • Kuylhee Kim;Donghyun Lee;Soyeon Jung;Chul Hoon Chung;Yongjoon Chang
    • 대한두개안면성형외과학회지
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    • 제25권3호
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    • pp.141-144
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    • 2024
  • A 76-year-old woman, initially thought to have a simple abscess on her right upper eyelid, presented to our department of plastic and reconstructive surgery. Enhanced three-dimensional facial computed tomography (CT) revealed an abscess on the right upper lid, with a pyomucocele present in the right frontal sinus, accompanied by bone erosion in the superior wall of the right orbit. Based on the results of the CT scan, we diagnosed an atypical Pott's puffy tumor (PPT) with an abscess on the upper lid originating from the frontal sinusitis. First, surgical incision and drainage were performed in our department, and a percutaneous vacuum drain was placed. To provide a more definitive treatment, endoscopic sinus surgery (ESS) was subsequently performed by otorhinolaryngologists. The patient was discharged without any complications 5 days after ESS. At a 1-year follow-up, no recurrence or notable neurological symptoms were observed. In the case we observed, the patient presented with an upper eyelid abscess and cellulitis, indicating possible orbital involvement. For such patients, a CT scan is necessary. Given the possibility of PPT, it is critical to perform a comprehensive differential diagnosis rather than defaulting to a straightforward approach involving abscess treatment.

중이에서 발견된 영유아 섬유성 과오종의 영상 소견: 증례 보고 (CT and MRI Features of Middle Ear Fibrous Hamartoma of Infancy: A Case Report)

  • 백상훈;김상현;임경재
    • 대한영상의학회지
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    • 제83권2호
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    • pp.420-424
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    • 2022
  • 중이의 영유아 섬유성 과오종은 매우 드물다. 저자들은 26개월 남아의 중이에서 진단된 사례를 영상의학적 소견을 중심으로 보고하고자 한다. CT 영상에서는 귓속뼈의 파괴가 없었으며 MRI에서는 지방과 섬유성 조직과 유사한 신호 강도를 보였다. 수술 후 조직학적 검사에서 영유아 섬유성 과오종으로 진단받았다. 중이의 영유아 섬유성 과오종은 드물지만, 유년기에 중이에서 관찰되는 종괴의 감별진단에 포함되어야 한다.

터널 및 지중매설물 시공에 따른 지반함몰 발생 원인 및 대책에 대한 지반공학적 조사 연구 (Geotechnical investigation on causes and mitigation of ground subsidence during underground structure construction)

  • 최신규;백승훈;안준범;권태혁
    • 한국터널지하공간학회 논문집
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    • 제18권2호
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    • pp.143-154
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    • 2016
  • 최근 국내 빈번하게 발생되고 있는 지반함몰 현상의 원인, 현황, 대책에 대하여 지반공학적인 접근 방법으로 조사하였다. 국내 발생된 지반함몰은 대부분 터널 굴착 공사와 지중매설관의 손상에 의한 것으로 나타났다. 용산역과 석촌 지하차도 지반함몰 사례와 같이, 굴착 공사 중 지반함몰은 지하수와 토사의 과다 유출이 주된 원인으로 나타났다. 특히, 충적층과 같은 연약지반에서의 기계식 굴착 시, TBM 굴착이 멈춘 지점에서 지반함몰 위험이 큰 것으로 나타났다. 서울시에서 발생된 지중매설관 손상으로 인한 지반함몰 사고를 종합하였을 때, 시공 시의 부주의, 노후화, 연약지반에서의 관의 부등침하 등이 지반함몰의 원인으로 나타났다. 터널 굴착 공사에 의한 지반함몰은 공사 시 발생되는 지하수, 토사의 이동에 대한 모니터링을 통해 대비할 수 있다. 지중매설관 손상으로 인한 지반함몰은 지중매설관의 생애주기 분석 및 유지관리 혹은 관 상부의 토압 분산 및 토압 지지력 증대를 통하여 대비할 수 있을 것으로 판단된다.