• Title/Summary/Keyword: Thickened Wall

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Control of Shock Wave/Boundary-Layer Interactions Using S-Shaped Mesoflaps (S-자형 플랩을 이용한 충격파와 경계층 간섭현상 제어에 관한 연구)

  • Lee Yeol
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.159-160
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    • 2002
  • New S-shaped aeroelastic mesoflaps are utilized to control normal shock/boundary-layer interactions. New generation of the mesoflaps is designed f3r a better rigidness and a good flow uniformity across the ulteractions. ,Major advantages of the mesoflap system can be a better total pressure recovery downstream of the interactions due to the lambda shock structure over the flap system, and a rehabilitation of the thickened boundary layer due to bleeding through a cavity underneath the flap system. Skin friction has been measured downstream of the interactions, using the laser interferometer skin friction (LISF) meter, which optically detects the rate of thinning of an oil film applied to the test surface. Various flap-thicknesses of the S-shaped mesoflap arrays are tested, and the results are compared to the solid-wall reference case. Overall, not much difference in the level of skin friction is noticed for the S-shaped flap arrays of various thicknesses, and its level is lower than the skin friction downstream of the solid-wall interaction

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(A)Study on Apartment Insulation Status and Insulation reinforcement Application (공동주택의 단열현황 조사 및 단열보강 적용방안에 관한 연구)

  • Jung, Ui-In;Kim, Bong-Joo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.226-227
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    • 2015
  • This research is to measure and analyze the thermal performance of the apartment structure and to evaluate and establish standards of thermal insulation defect in order to make the basic data necessary for determining the degree of the thermal performance degradation and for repairing and reinforcing the exterior wall of the existing apartment. The following conclusions could be derived thorough the investigation of outer wall temperature distribution and the insulation assesment experiments using a model of specimens for the apartment houses' outer walls. It was confirmed that for the thermal performance through the insulating material thicknesses 5cm, 8cm in walls, the thermal insulation thickened by 3cm, from 5cm to 8cm, but that the actual temperature difference reached only about 1 ~ 2℃. This implies that the thermal performance improvement using the thermal insulation in walls is not significant and that it is difficult to insulate the thermal bridge area.

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Numerical Analysis on the Flow Field and Heat Transfer Characteristics of Longitudinal Vortices in Turbulent Boundary Layer - On the Common Flow Down - (3차원 난류경계층 내에 존재하는 종방향 와동의 유동장 및 열전달 특성에 관한 수치해석(I) - Common Flow Down에 관하여 -)

  • Yang Jang-Sik
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.9
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    • pp.789-798
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    • 2005
  • This paper is a numerical study concerning how the interactions between a pair of the vortices effect flow field and heat transfer. The flow field (common flow down) behind a vortex generator is modeled by the information that is available from studies on a half-delta winglet. Also, the energy equation and the Reynolds-averaged Wavier-Stokes equation for three-dimensional turbulent flows, together with a two-layer turbulence model to resolve the near-wall flow, are solved by the method of AF-ADI. The present results predict that the boundary layer is thinned in the regions where the secondary flow is directed toward the wall and thickened where it Is directed away from the wall. Although some discrepancies are observed near the center of the vortex core, the overall performance of the computational model is found to be satisfactory.

Development of Differential Diagnosis and Treatment Method of Reproductive Disorders Using Ultrasonography in Cows V, Differential Diagnosis of Ovarian Cysts in Slaughtered Cows (초음파검사에 의한 소의 번식장애 감별진단 및 치료법 개발 V, 도축우에서 난소낭종의 감별진단)

  • 손창호;강병규;최한선;강현구;임원호;박상국;오기석;서국현
    • Journal of Veterinary Clinics
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    • v.16 no.1
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    • pp.138-144
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    • 1999
  • To establish the differential diagnosis and treatment method in bovine ovarian cysts, specially ovarian cysts with corpus luteum, serum progesterone (P$_4$) concentration and ultrasonography for measuring the cystic wall thickness and diameter of cyst and corpus luteum were investigated from slaughtered cows with ovarian cysts. Ovarian cysts were classified 8 types by the number of cyst, cystic wall thickness and present of corpus luteum. Ovarian cysts with corpus luteum were 11 (13.6%) of 81 cows and ovarian cysts without corpus luteum were 70 (86.4%) cows. The incidence rates of 8 various types of ovarian cysts were as follows; 2Ba 33.3%, 2Aa 25.9% and 2Bb 14.8%, respectively. The incidence rates of ovarian cysts without corpus luteum were follicular cyst 59.2% and luteal cyst 27.2%. The cystic wall thickness were 2Ab 3.7 mm and 2Bb 3.5 mm, and the serum P4 concentrations were above 2.0 ng/ml in 1Aa, 1Ab, 1Ba, 2Ab and 2Bb, respectively. In ovarian cysts with corpus luteum, the correlation coefficients between corpus luteum area and serum P$_4$ concentration were 0.45. In ovarian cysts without corpus luteum, there was significantly positive correlations between cystic wall thickness and serum P$_4$ concentration ($r^2$= 0.54, p<0.01). These results indicate that PGF$_2$$\alpha$ analogues can be choice for treatment of ovarian cysts with corpus luteum and above 3 mm the cystic wall thickness because serum P$_4$ concentrations were above 2.0 ng/ml in ovarian cysts with corpus luteum and thickened cystic wall. In conclusion, it is suggest that ultrasonography is useful diagnostic tool for diagnosis and selection of treatment remedy in cystic ovaries of bovine.

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Differential diagnosis of ovarian cysts and selection of therapeutic drugs in slaughtered cows (도축우 유래 난소낭종의 감별진단 및 치료제 선택)

  • 박상국;최동식;박장일;정대영
    • Korean Journal of Veterinary Service
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    • v.23 no.2
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    • pp.125-132
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    • 2000
  • To establish the differential diagnosis and treatment method in bovine ovarian cysts, specially ovarian cysts with corpus luteum, serum progesterone ($P_4$) concentration and ultrasonography for measuring the cystic wall thickness and diameter of cyst and corpus luteum were investigated from slaughtered cows with ovarian cysts. Ovarian cysts were classified 8 types by the number of cyst, cystic wall thickness and present of corpus luteum. Ovarian cysts with corpus luteum were 11 (13.6%) of 81 cows and ovarian cysts without corpus luteum were 70 (86.4%) cows. The incidence rates of 8 various types of ovarian cysts were as follows; 2Ba 33.3%, 2Aa 25.9% and 2Bb 14.8%, respectively The Incidence rates of ovarian cysts without corpus luteum were follicular cyst 59.2% and luteal cyst 27.2%. The cystic wall thickness were 2Ab 3.7mm and 2Bb 3.5mm, and the serum P4 concentrations were above 2.0 ng/$m\ell$ in IAa, tAb, IBa, 2Ab and 2Bb, respectively In ovarian cysts with corpus luteum, the correlation coefficients between corpus luteum area and serum $P_4$ concentration were 0.45. In ovarian cysts without corpus luteum, there was significantly positive correlations between cystic wall thickness and serum $P_4$ concentration($r^2$ = 0.54, p<0.01). These results indicate that $PGF_2$$\alpha$ analogues can be choice for treatment of ovarian cysts with corpus luteum and above 3mm the cystic wall thickness because serum $P_4$ concentrations were above 2.0 ng/$m\ell$ in ovarian cysts with corpus luteum and thickened cystic wall. In conclusion, it Is suggested that ultrasonography is useful diagnostic tool for diagnosis and selection of treatment remedy in cystic ovaries of bovine.

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Bowel Wall Thickening on Computed Tomography in Children: A Novel Method of Measurement and Its Clinical Significance

  • Lee, Do Kyung;Cho, Ky Young;Cho, Hyun-hae;Seo, Jeong Wan
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.24 no.3
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    • pp.279-287
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    • 2021
  • Purpose: The clinical implications of bowel wall thickening (BWT) on abdominal computed tomography (CT) among children are unknown. We aimed to suggest a new method for measuring BWT and determining its clinical significance in children. Methods: We retrospectively analyzed 423 patients with acute abdomen who underwent abdominal CT; 262 were classified into the BWT group. For this group, the pediatric radiologist described the maximal bowel wall thickness (MT), normal bowel wall thickness (mm) (NT), and their ratios for each segment of the bowel wall. Results: In the thickened bowel walls, the thickness differed significantly between the small bowel (6.83±2.14 mm; mean±standard deviation) and the colon (8.56±3.46 mm; p<0.001). The ratios of MT to NT in the small bowel (6.09±3.17) and the colon (7.58±3.70) were also significantly different (p<0.001). In the BWT group, 35 of 53 patients had positive fecal polymerase chain reaction results; 6 patients infected with viruses predominantly had BWT in the small intestine, while the terminal ileum and the colon were predominantly affected in 29 patients with bacterial infections. In the initially undiagnosed 158 patients with BWT, the symptoms improved spontaneously without progression to chronic gastrointestinal disease. Conclusion: This study provides a clinical reference value for BWT in the small intestine and colon using a new method in children. The BWT on abdominal CT in children might indicate nonspecific findings that can be observed and followed up without additional evaluation, unlike in adults.

MR Images of Bowel Wall Thickening in Patients with Minimal to Moderate Cirrhosis: Comparison with Clinical Findings (경증과 중등도 간경화 환자에서 장관 비후의 MR 영상: 임상소견과의 비교)

  • Mitchell Donald G.;Hann Hie-Won L.;Parker Laurence;Kim, Mi-Young
    • Investigative Magnetic Resonance Imaging
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    • v.10 no.2
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    • pp.81-88
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    • 2006
  • Purpose : To evaluate the MR imaging findings of bowel wall thickening in patients with minimal to moderate cirrhosis, and analyze their clinical significances comparing with laboratory findings. Materials and Methods : We assessed retrospectively the MRI findings of 123 patients with minimal to moderate cirrhosis, and compared these with the clinical laboratory findings. We evaluated the involved sites and MR image findings of thickened bowel wall, as well as the presence of collateral vessels, ascites, and splenic size. These were compared with serum albumin and bilirubin levels, and prothrombin time. Results : Gastrointestinal wall thickening was detected at 37 sites in 25 patients (20%), and more frequently detected in moderate cirrhosis (29%) than in minimal cirrhosis (17%). Jejunum and ascending colon were the most common sites of bowel wall thickening; each was involved at 22 and 9 sites, respectively. Ascending colonic wall thickening was more commonly detected in moderate cirrhosis than in minimal cirrhosis. The thickened bowel wall showed symmetric contour, high signal intensity on T2-weighted images, mixed iso- and low signal intensity on T1-weighted images, and homogeneous or target-like enhancement. Serum albumin level was significantly lower in patients with bowel wall thickening ($3.3{\pm}0.9$ g/dl vs. $3.9{\pm}0.7$ g/dl; p=0.0024). Serum bilirubin level was significantly higher in patients with bowel wall thickening ($1.7{\pm}1.0$ mg/dl vs. $1.4{\pm}1.2$ mg/dl; p=0.0160). Bowel wall thickening did not significantly correlate with the presence of collateral vessels, ascites, splenic size, and prolongation of prothrombin time. Conclusion : In minimal to moderate cirrhosis, the MR imaging evaluation of bowel wall thickening was useful for estimating the severity of cirrhosis and laboratory findings.

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Morphological Characteristics of Hyphal Interaction between Grifola umbellata and its Companion Fungus

  • Xing, Xiao-Ke;Guo, Shun-Xing;Lee, Min-Woong
    • Mycobiology
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    • v.33 no.1
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    • pp.1-6
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    • 2005
  • Morphological characteristics of hyphal interaction between Grifola umbellata (Pers. Ex Fr.) Pilat and its companion fungus which related to sclerotia formation from hyphae were investigated by external observations, light microscopy and transmission electron microscopy (TEM). External observations showed that a dense antagonism line was formed by both G. umbellata and companion fungus after their hyphae contacted each other in dual culture. Many hyphal strands emerged on the colony of G. umbellata and differentiated to sclerotia from where hyphal strands crossed. Light microscope observations revealed the process of antagonism line formation. Mature antagonism with structural differentiation, was composed of three main layers: the rind, the rind underlayer and the hypha layer. TEM observations showed that after colonies hyphal contact, a series of reactions always occurred in both G. umbellata and companion fungus. Cells in the center of antagonism line were dead. Cells of G. umbellata adjacent to the antagonism line were usually large and hollow, with unilateral thickened wall, whereas those of companion fungus were empty, with thin or thick wall. Both hyphal interaction at the antagonism line may be one of the main reasons for sclerotia of G. umbellata differentiation from hypha.

An Experimental Study on the Effect of Fluid Flow and Heat Transfer Characteristics by the Longitudinal Vortices (종방향 와동이 유체유동 및 열전달 특성에 미치는 영향에 관한 실험적 연구)

  • 양장식;김은필
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.9
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    • pp.843-852
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    • 2000
  • The flow characteristics and the heat transfer rate on a surface by interaction of a pair of vortices were studied experimentally. The test facility consisted of a boundary-layer wind tunnel with a vortex introduced into the flow by half-delta winglet protruding from the surface. In order to control the strength of the longitudinal vortices, the angles of attack of the vortex generators were varied from $\pm20\;degree\;to\;\pm45$ degree, but spacings between the vortex generators were fixed to 4 cm. The 3-dimensional mean velocity measurements were made using a five-hole pressure probe. Heat transfer measurements were made using the thermochromatic liquid to provide the local distribution of the heat transfer coefficient. By using the method mentioned above, the following conclusions were obtained from the present experiment. The boundary layer was thinned in the regions where the secondary flow was directed toward the wall and thickened where it was directed away from the wall. The peak augmentation of the local heat transfer coefficient occurred in the downwash region near the point of minimum boundary-layer thickness.

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Unusual Necrotizing Uterine Adenocarcinoma in a Dog

  • Kim, Tae-Jung;Shin, Sung-Shik;Park, Sang-Ik
    • Journal of Embryo Transfer
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    • v.32 no.4
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    • pp.325-329
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    • 2017
  • A 2-year-old female Maltese dog was admitted with a history of pyometra and resulting peritonitis and septicemia. Uterine specimen sampled by ovariohysterectomy was processed routinely for histopathological observation. Grossly, the uterine mucosa was covered with necrotic debris and on the cut surface, lesion extended into the uterine wall. Microscopically, severe necrosis was observed throughout thickened mucosa, submucosa, and wall of uterus. Tumorous lesions composed of anaplastic cells with bizarre nuclei or tubular structures of cuboidal to short columnar cells were infrequently observed around the necrotic lesions and muscular layer far from necrotic areas. Immunohistochemically, central necrotic area with ambiguous cell and tissue structures, peri-necrotic tumor lesions, and muscular layer were strongly positive for cytokeratin. Since huge necrosis of adenocarcinoma lesions in this case made it difficult to diagnose, immunohistochemical results enable to diagnose as a severe necrotizing adenocarcinoma. Thus, histopathological and immunohistochemical findings in this case may serve as an important knowledge to diagnose uterine adenocarcinoma with huge necrosis in the veterinary field.