• Title/Summary/Keyword: Mass wall

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Heat/Mass Transfer and Pressure Drop of Square Duct with V-shape Ribs (쐐기형 요철이 설치된 사각덕트에서의 열전달 및 압력강하 특성)

  • Choi, Chung;Rhee, Dong-Ho;Cho, Hyung-Hee
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.280-287
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    • 2001
  • The present study investigates convective heat/mass transfer and flow characteristics inside the rib-roughened cooling passage of the gas turbine blades. A square duct with rectangular ribs is used and $\wedge-$ and V-shape ribs with $60^{\circ}$ attack angle are installed on the test plate surfaces. Naphthalene sublimation technique is employed to determine the detailed local heat transfer coefficients using the heat and mass transfer analogy. The ribs disturb the main flow resulting in the recirculation and secondary flows near the ribbed wall and the vortices near the side-wall. The local heat transfer and the secondary flow in the duct are changed largely according to the rib orientation. A square duct with $\wedge$ and V-shape ribs has two pairs of secondary flow because of the rib arrangement. So, the duct has complex heat/mass transfer distribution. The average heat/mass transfer coefficient and pressure drop of $\wedge-$ and V-shape ribs are higher than those with $90^{\circ}$ and $60^{\circ}$ attack angles. The average heat/mass transfer coefficient on the $\wedge-shape$ ribs is higher than that on the V-shape ribs. Also, the uniformity of heat/mass transfer coefficient on discrete ribs is higher than that on continuous rib.

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Diagnostic Imaging of Paraprostatic Cyst with Osseous Metaplasia in a Dog (개에서 골화생을 동반한 전립선 주위종의 영상의학 증례)

  • Choi, Ji-Hye;Keh, Seo-Yeon;Kim, Sung-Soo;Choi, Hee-Yeon;Kim, Hyun-Wook;Yoon, Jung-Hee
    • Journal of Veterinary Clinics
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    • v.27 no.4
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    • pp.468-473
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    • 2010
  • A 6-year-old intact male Doberman pinscher presented with a thin soft stool and urinary signs. On radiography, three masses were observed in the caudal abdomen. One mass was described as a large, round, mineralized mass, with an "eggshell" appearance. The second mass was located caudal to the mineralized mass, and the third mass was located between the two masses. The second and the third masses had a soft tissue density. Ultrasonography was performed to identify the features and the origins of the masses. The first mass contained a large amount of anechoic fluid and had a thin wall; it was determined to be a cyst. Strong acoustic shadowing artifact was created by the mineralized cystic wall. Caudal to the cyst, the second mass was shown to be the prostate. A hypoechoic stalk connected the prostate and the cyst, which represented the cyst as a paraprostatic cyst with mineralization. The third mass was the normal urinary bladder. The cyst was removed surgically and confirmed by histopathologic examination. This report described typical clinical findings, diagnostic imaging, and treatment of a paraprostatic cyst.

Heavy-impact sound insulation performance according to the changes of dry flooring structure in wall structure

  • Cho, Jongwoo;Lee, Hyun-Soo;Park, Moonseo;Lim, Hohwan;Kim, Jagon
    • International conference on construction engineering and project management
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    • 2017.10a
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    • pp.89-98
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    • 2017
  • The floor heating method generally uses a wet construction method including the installation of resilient material, lightweight foam concrete, heating piping, and finishing mortar. Such a wet construction method not only delays other internal finishing processes during curing period for two mortar pouring process, but also has a disadvantage that it is difficult to replace the floor heating layer when it deteriorated because it is integrated with the frame. Dry floor heating construction method can be a good alternative in that it can solve these defects. Conversely, when it applied to the wall structure that is vulnerable to the interlayer noise compared with the column-beam structure, the question about the heavy-impact sound(HIS) insulation performance is raised. Therefore, conventional dry floor heating method is hard to apply to the wall structure apartments. Therefore, for the purpose to improve the applicability of dry floor heating method in wall structure apartments, this study investigated the change of floor impact sound, especially HIS insulation performance which is one of the required performance for the floor structure. This study tried to examine whether the change of heavy-impact sound pressure level(SPL) shows a tendency at the significant level according to the shape and mass of the floor structure. Through filed experiments on wall structure apartment, this study confirmed that the form of the raised floor shows better HIS insulation performance than the fully-supported form. In addition, it was also confirmed that the HIS insulation performance increases with the mass on the upper part. Moreover, this study found the fact that a mass of about 30 kg/m2 or more should be placed on the upper structure to reduce the heavy-impact SPL according to the bang machine measuring method. Although this study has a limit due to insufficient experiment samples, if the accuracy of this study is increased, it will contribute to the diffusion of dry floor heating by setting the HIS insulation performance target and designing the dry floor heating structure that meets the target.

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Thermal Cracking Control of Mass Concrete by Vertical Pipe Cooling Method (연직파이프쿨링 공법에 의한 매스콘크리트 온도균열 제어)

  • Seo, Tae-Seok;Lim, Chang-Keun;Cho, Yun-Gu
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.2 no.3
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    • pp.233-238
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    • 2014
  • In case of the slender mass concrete like attached wall, retaining wall and bridge tower, the low heat cement and the control joint are mainly used for thermal cracking control. However, even if these cracking control methods are considered, it is impossible to control thermal cracks perfectly, because the external restraint is largely in these mass concrete. Because these cracks occurring in slender mass concrete members almost penetrate concrete member, the special cracking control is demanded in these mass concretes. The vertical pipe cooling method improving existing pipe cooling method was developed for the active thermal cracking control of slender mass concrete, and applied at the field attached wall. In results, the maximum temperature dropped more than $10^{\circ}C$ by vertical pipe cooling method, and the cracks decreased about more than 50%.

Sinonasal Undifferentiated Carcinoma - A Case Report - (부비동과 비의 미분화 암종 - 1예 보고 -)

  • Shin, Mi-Kyung;Chae, Yang-Seok
    • The Korean Journal of Cytopathology
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    • v.8 no.1
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    • pp.98-102
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    • 1997
  • Sinonasal undifferentiated carcinoma(SNUC) is a distinct, relatively rare neoplasm arising in the nasal cavity and paranasal sinuses composed of undifferentiated epithelial cells and clinically characterized by a fulminant course. We report a case of SNUC in a 56-year old man who have had bilateral neck masses since one month ago before coming to our hospital. The paranasal computed tomography showed soft mass density in the left maxillary sinus and the nasal cavity with bone destruction in the anterior medial and the inferior maxillary sinus wall. This mass was extruded into the left orbital wall. Biopsy of the nasal mass and fine needle aspiration(FNA) of the neck mass were done. FNA revealed medium-sized neoplastic cells forming clusters or individually dispersed. Nuclei were round to oval, slightly to moderately pleomorphic, and hyperchromatic. Chromatin was finely granular, but occasionally was coarsely granular. Nucleoli varied from large to inconspicuous and the cytoplasm was scanty.

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Performance characterization of liquid desiccant system with extended surface (확장표면을 적용한 액체식 제습시스템의 성능특성에 관한 연구)

  • Jang, Young-Soo;Song, Gwi-Eun;Lee, Dae-Young
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.639-644
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    • 2009
  • This study presents the new idea of liquid desiccant system with extended surface to reduce the system size. The extended surface is inserted between vertical cooling/heating tubes to increase the mass transfer area, and the liquid desiccant flows through the tube wall and the extended surface. Mathematical models for heat and mass transfer between liquid desiccant and air stream at tube wall and extended surface are provided. Dimensionless design parameters governing heat and mass transfer phenomena around the tube and the extended surface are identifier, and dimensionless operating parameters depicting system operating condition including flow rate ratio between dehumidification/regeneration processes, and mass flow rate ratio between air stream and liquid desiccant are explained. The effects of the parameters on system performance are summarized.

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Teratoma with Malignant Transformation in the Anterior Mediastinum: A Case Report

  • Jung Im Jung;Seog Hee Park;Jae Gil Park;Sun Hee Lee;Kyo Young Lee;Seong Tai Hahn
    • Korean Journal of Radiology
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    • v.1 no.3
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    • pp.162-164
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    • 2000
  • Malignant transformation of teratoma in the anterior mediastinum is rare; the mass usually has a long history and is seen in older patients. We report a case of teratoma with malignant transformation in the anterior mediastinum, complicated by rupture. CT revealed a lobulated, inhomogeneous cystic mass with a fat component and wall calcifications. The lateral wall was disrupted and consolidation in the adjacent left upper lobe was noted, suggesting rupture. A heterogeneously enhanced solid portion, obliterating the fat plane between the mass and the great vessels was present in the medial aspect of the mass, and pathologic examination demonstrated the presence of adenocarcinoma.

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Experience of Reconstruction of an Extensive Chest Wall Defect with Extended External Oblique Musculocutaneous Flap (거대 흉벽 결손에 대한 확장 외복사근 근피판을 이용한 흉벽재건 치험례)

  • Kim, Dae-Hee;Kim, Chung-Hun;Song, Seung-Yong
    • Archives of Plastic Surgery
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    • v.37 no.3
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    • pp.277-280
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    • 2010
  • Purpose: The resection of locally advanced or recurred breast cancers frequently result in large chest wall defects and it leads to a great challenges to cover. Generally simple skin grafts are not a practical option for patients because of their poor cosmetic appearance and prognosis. The latissimus dorsi and rectus abdominis musculocutaneous flap have traditionally been recommended for closure of these large defects. Though the cosmetic result of reconstruction using these flaps is often excellent, but has significant drawbacks. Therefore, we thought that chest wall reconstruction using the external oblique musculocutaneous flap can be an alternative method for extensive chest wall defect related to large, locally advanced breast carcinoma. Methods & Results: We present a case of a 50-year-old Korean female, refered to our department with a left breast tumor for 10 months. CT demonstrate a large tumor on the left anterior chest wall and multiple nodules of varying size in the cervical areas and liver. FDG-PET showed areas of hot uptake throughout the left chest wall, mediastinum and liver. Biopsy was consistent with invasive ductal carcinoma (Grade III). The initial tumor was considered inoperable, so a series of chemotherapy was initiated. Though the size of the breast mass was slightly decreased, the patient continued to suffer from purulent discharge, unpleasant odor and contact bleeding of the mass, the salvage mastectomy was performed. Conclusion: We could reconstruct $23{\times}16\;cm$ sized large chest wall defect, resulting from the resection of a locally advanced breast carcinoma, using an external oblique musculocutaneous flap successfully. Immediate postoperatively checked flap was healthy. Overall result was good without any significant complications and discharged 3 weeks after operation.

Hydrodynamic coupling distance between a falling sphere and downstream wall

  • Lin, Cheng-Chuan;Huang, Hung-Tien;Yang, Fu-Ling
    • Coupled systems mechanics
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    • v.7 no.4
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    • pp.407-420
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    • 2018
  • In solid-liquid two phase flow, the knowledge of how descending solid particles affected by the presence of downstream wall is important. This work studies at what interstitial distance the velocity of a vertically descending sphere is affected by a downstream wall as a consequence of wall-modified hydrodynamic forces through a validated dynamic model. This interstitial distance-the hydrodynamic coupling distance ${\delta}_c-is$ found to decay monotonically with the approach Stokes number St which compares the particle inertia to viscous drag characterized by the quasi-steady Stokes' drag. The scaling relation ${\delta}_c-St-1$ decays monotonically as literature below the value of St equal to 10. However, the faster diminishing rate is found above the threshold value from St=10-40. Furthermore, an empirical relation of ${\delta}_c-St$ shows dependence on the drop height which clearly indicates the non-negligible effect of unsteady hydrodynamic force components, namely the added mass force and the history force. Finally, we attempt a fitting relation which embedded the particle acceleration effect in the dependence of fitting constants on the diameter-scaled drop height.